Tag: News

• TikTok Shop reorganized its global e-commerce product and data science teams, per a company memo.
• E-commerce product and design lead Zhou Sheng stepped aside in early December as part of the change.
• The move comes after TikTok Shop drove over $500 million in US sales during the Black Friday week.

After a blockbuster Black Friday week, TikTok and its owner ByteDance are shaking up their global e-commerce product and data science teams, according to two company staffers and a December memo viewed by Business Insider.

The move was designed to streamline collaboration in areas like artificial intelligence, as well as "improve operational efficiency," per the memo.

As part of the change, which was implemented in the first week of the month, global e-commerce product and design team leader Zhou Sheng is stepping aside. Zhou helped build the company's e-commerce product and "greatly facilitated" its global development, ByteDance e-commerce head Bob Kang wrote in his memo. After the restructuring, regional e-commerce product and user growth managers will report to Chen Songlin, a ByteDance executive who earlier worked on TikTok's Chinese sister app, Douyin.

The company also restructured its global e-commerce data science team. Managers will report to the executive Zhang Heng with the goal of centralizing the group's measurement and AI strategies, per the memo.

AI has been a big focus at TikTok Shop this year, one of the staffers said.

"Pretty much every team is working on it to some degree," the employee said. Some of the work is customer-facing, while other efforts are designed to improve internal efficiency, they added.

TikTok Shop has undergone a series of restructurings and job cuts over the past year as the company has sought to get its e-commerce business off the ground in key markets like the US. In April, the company cut workers on its governance and experience team and restructured the group, handing more power to staffers based in Singapore or China.

TikTok Shop's US staff have been under pressure to perform this year after global leadership felt the group failed to meet performance expectations in 2024, BI previously reported. The e-commerce platform, which officially launched in the US in late 2023, faced headwinds earlier this year as its sellers stared down threats of a political ban and rising import costs related to tariffs.

Things appear to be looking up. This holiday season, the company said it drove over $500 million in US sales during the four-day window between Black Friday and Cyber Monday. More household-name brands have joined TikTok Shop in the US recently, including Disney, Ralph Lauren, and Samsung.

Fears of a potential ban have faded for some merchants, as the Trump administration has repeatedly signed executive orders delaying enforcement of the law that requires ByteDance to sell its US business or face removal from app stores. In September, the Trump administration said it had approved a $14 billion sale of the US app in a deal that could involve Oracle, Larry Ellison, Michael Dell, and Rupert Murdoch.

TikTok did not respond to a request for comment.

• South Korean shipbuilder HJ Shipbuilding and Construction won a US Navy ship maintenance contract.
• It's the latest South Korean company to get involved in US Navy repair work.
• Washington is increasingly relying on Seoul for shipbuilding projects abroad and in the US.

South Korean shipyards are steadily becoming an integral part of US Navy maintenance work. Following in the footsteps of some of the nation's shipbuilding giants, another local shipbuilder just secured a new contract.

HJ Shipbuilding and Construction announced on Monday that it won a deal to service a US Navy vessel — the Lewis and Clark-class dry cargo ship USNS Amelia Earhart — as Washington increasingly turns to South Korea's impressive commercial shipbuilding sector to support strained American yards and keep the fleet afloat.

The maintenance contract is with the Navy's Naval Supply System Command and Military Sealift Command.

The work on the Amelia Earhart — which will include an inspection of the ship's hull and systems, follow-up repairs and replacements, and a paint job — will begin in January 2026 at the Yeongdo Shipyard in Busan. The vessel will be delivered to the Navy by the end of March.

The Amelia Earhart is one of the Navy's supply ships that refuels and resupplies aircraft carriers and warships at sea. Its overhaul adds to a growing list of US Navy work going to South Korean companies.

Major South Korean shipbuilder Hanwha Ocean finished repairs on the USNS Wally Schirra, another Lewis and Clark-class vessel, in March, marking a first for a South Korean shipyard. And then HD Hyundai Heavy Industries, one of the country's largest shipbuilders, received a maintenance contract for another ship in the class, the USNS Alan Shepard.

HJ Shipbuilding and Construction said it's the first midsize shipbuilder in South Korea to win a maintenance contract with the US Navy.

While smaller voyage repairs to US Navy ships occur regularly at allied yards, the continued contract wins for South Korean shipyards highlight the growing shipbuilding collaboration between Washington and Seoul.

That partnership, which has included business deals for South Korean companies abroad as well as investments in American yards, is part of a broader willingness by the Trump administration to rely on its Pacific ally amid efforts to fix US shipbuilding issues.

Billions of dollars are being put into modernizing US shipyards and addressing workforce and training issues as South Korea's government calls its investments a plan to "Make American Shipbuilding Great Again." The US is also turning to Japan, another large shipbuilder, for assistance.

South Korea and Japan are the second and third largest shipbuilders in the world, respectively, and Navy leadership is increasingly recognizing their value in this sector. China, however, dominates the shipbuilding industry, relying heavily on its dual-use yards, workforce, and equipment to make military and commercial vessels at a rapid pace.

• I spent the holidays away from home for the first time by going on a 22-day cruise over Christmas. 
• I woke up on Christmas to views of Antarctica, but I missed my traditions and the rest of my family.
• Though the cruise was unforgettable and nice, I probably wouldn't travel over the holidays again.

Despite traveling fairly frequently, I'd never been away from home for Christmas until recently

In 2023 (into 2024), I spent Christmas and New Year's Eve on a 22-day Holland America cruise around South America and Antarctica.

I traveled with my grandma and cousin, and our cruise began in Buenos Aires, Argentina, and ended in Santiago, Chile.

I felt hesitant about booking a cruise that took place over the holidays, but I figured it'd be worth missing my traditions for one year to wake up to a view of Antarctica on Christmas morning.

Though Holland America had fantastic decorations, unbeatable views, and fun holiday-themed events, I felt homesick.

It didn't feel like Christmas in the week leading up to it

It was so hot in many of the ports that we stopped at, like Buenos Aires and Puerto Madryn, Argentina, because it was summer in the Southern Hemisphere.

It felt extra strange because I was traveling from Chicago, where we always have a chilly Christmas.

Due to the warm weather, it was easy to forget that Christmas was just around the corner — and it felt odd, but delightful, to see decorated cities.

One of my favorite stops was in Puerto Aysén, Chile, where the town's main square was filled with lights and decorations depicting Santa and reindeer.

Fortunately, the boat was extravagantly decorated

One of the most striking features on board was the ship's gingerbread village. The elaborate setup was just one of the beautiful decorative areas on the ship.

Several Christmas trees were also displayed throughout the boat.

It wasn't just the Holland America crew that decorated — other guests brought tinsel, ornaments, and small decorations to hang from their room's doors and mailboxes. It added to the ship's festive spirit.

There were festive activities, and Santa visited the ship

There were plenty of holiday-themed activities to take part in on the ship, too, like decorating gingerbread ornaments and creating origami Christmas trees.

We used these to decorate our room, and ended up placing the presents we'd brought near a small origami tree. Having our room slightly decorated helped us feel less homesick and more excited for the holidays.

It was also nice that, after breakfast on Christmas Day, the captain announced that there was an unidentified object flying over our ship.

Minutes later, it was identified as Santa, who would be stopping by to bring presents to the children on board. Santa and some elves then appeared on the ship's main stage, handing out small gifts to kids and hot chocolate to adults.

Festivities continued on New Year's Eve

As the clock ticked down to midnight on New Year's Eve, there was a bustling party on the Oosterdam's lido deck.

It featured the house band playing hits from several decades and complimentary flutes of sparkling wine.

The party took over the pool area, so there was no swimming, but the hot tubs were still in full use as ice-packed coolers for bottles of bubbly.

I had a great time on the cruise, but I don't think I'd ever travel over the holidays again

Being away from home during the holidays was tough, but getting my first view of Antarctica on Christmas morning was an unforgettable gift.

That morning, we were greeted with a close-up view of Elephant Island, one of the furthest reaches of Antarctica's South Shetland Islands.

It was a dream come true being there, but when it comes to the holidays, my heart will always be at home.

This story was originally published on January 16, 2024, and most recently updated on December 15, 2025.

• Business Insider spoke to Rob Reiner and his son Nick Reiner in 2016.
• Their film, "Being Charlie," is based on Nick's battle with drug addiction.
• On Monday, Nick was arrested in connection with the deaths of his parents, Rob Reiner and Michele Singer Reiner.

The sudden deaths Sunday of legendary director Rob Reiner and his wife, Michele Singer Reiner, reverberated through Hollywood. Now, the arrest of Reiner's son Nick on Monday on a murder charge in connection with his parents' deaths is shedding new light on the internal struggles of the famous family.

Business Insider spoke with Nick Reiner and Rob Reiner in 2016 while attending the Toronto International Film Festival, where the pair were premiering their movie "Being Charlie," which is based on Nick's experiences with drug abuse.

The movie focuses on 18-year-old Charlie (Nick Robinson) as he struggles with addiction to heroin and cocaine. As Charlie jumps in and out of rehab, the aggravation of his actor-turned-politician father ("Princess Bride" star Cary Elwes) grows, as he struggles to figure out how to help his son.

Nick began working on the script with a fellow addict, Matt Elisofon, while spending four years at a Los Angeles rehab facility. After the script was rejected as a TV series, Nick and Elisofon turned to Rob to come on and direct it as a feature film.

Nick told Business Insider at the time that working with his father on a film about his struggles with addiction and their relationship as a family was complicated but healing.

"It was a real corrective emotional experience," Nick told Business Insider in 2016 of watching his movie premiere at TIFF.

"I relied on him," Rob said of his son. "He's the heart and soul of the film."

The movie had a blink-and-you-miss-it release, playing in four theaters for one week in May 2016.

"We were healing as we were going along," Nick said in 2016. "And it all doesn't happen overnight. Certain things we hadn't dealt with for a while, but we were able to through this movie. It didn't fix everything, but it really tapped into — "

Nick paused to find the words, then his father, sitting across from Nick, finished for him.

"It forced me to really have to understand what he had been going through for a long time," Rob said.

We spoke with three families who told us what it really takes to inherit and keep a family business alive. They run a decades-old Chicago barbecue sauce brand, a Greek bakery, and one of the last fabric-flower businesses in New York.

(Sponsored by Edward Jones)

• After traveling to all 50 states, I've come across some charming cities to visit in the winter.
• Healdsburg, California, and Aspen, Colorado, feel especially magical during the holidays.
• I also love visiting Park City, Charleston, and Boulder for cozy winter vibes.

When it comes to winter travel, there's nothing quite like visiting a picture-perfect town with charming local shops, friendly faces, and festivals for every occasion.

After visiting all 50 states, I've discovered that some cities feel like Hallmark movies in real life — especially during the holidays. Here are some of my favorites to visit for cute winter vibes.

Boulder, Colorado, is full of cozy shops and restaurants.

As a Boulder resident, I may be biased, but this Colorado city feels made for a Hallmark movie. Downtown, the pedestrian-only Pearl Street is lined with local shops, cozy restaurants, and every outdoor-gear store you could imagine.

During the holidays, the streets twinkle with colorful lights, and frequent festivals, art markets, and a festive parade bring the town to life.

Towering above it all, the Boulder Star on Flagstaff Mountain — a massive illuminated landmark visible from miles away — casts a magical glow over the city, making the season feel truly special.

Healdsburg, California, is stunning during the holidays.

Healdsburg, California, is one of my favorite small towns in the country.

The downtown area is perfectly walkable with boutique shops, tasting rooms, and cozy cafés centered around a gorgeous town square.

I especially love visiting during "Merry Healdsburg," the tree-lighting event where Santa appears, the whole town comes out, and there are carriage rides, live music, and a holiday market.

Throughout the season, various holiday events and decorations create a storybook winter wonderland at every turn.

Aspen, Colorado, feels like a winter wonderland.

I love visiting Aspen, Colorado, year-round, but the holidays have a way of making the whole town feel magical.

I always enjoy wandering the pedestrian-only streets, with charming (and upscale) shops and restaurants against the dramatic mountain backdrop. Plus, there are plenty of opportunities to ski.

Each year, I make it a point to watch the Snow Polo Championship, which spectators can easily access from downtown Aspen. Whether you attend as a ticket holder or a free spectator, it's a truly unique holiday experience.

Park City, Utah, truly feels like the set of a Hallmark movie.

I love visiting Park City during the holidays. There's something special about seeing the snowy streets and lights while walking along the historic Main Street, with its charming Western shops and upscale restaurants.

Skiing in the area adds to the magic, and all the festive decorations and seasonal events make it feel like the perfect winter escape.

Charleston is beautifully decorated during the holiday season.

In my opinion, there's nothing quite like visiting Charleston during the holiday season.

Strolling along the Battery and getting lost along the historic cobblestone streets of the French Quarter and South of Broad, I'm surrounded by pastel-colored homes, wrought-iron balconies, and beautifully decorated architecture that looks like it was made for a holiday scene.

The cozy shops, cafés, and hidden courtyards add to the magical atmosphere. I love shopping for holiday gifts, stopping into special Christmas pop-up shops, and admiring the over-the-top decor and festive lights that seem to cover every surface downtown.

Bayfield, Wisconsin, is a quaint town with cozy Midwestern vibes.

Situated on the shores of Lake Superior, Bayfield, Wisconsin, is filled with historic brick storefronts, cozy cafés, and local boutique lodging, all with a welcoming Midwestern vibe.

During Christmas in Bayfield, twinkling lights line the streets, local shops host craft markets, and festive events make the harbor area feel friendly, magical, and almost surreal.

Vail, Colorado, is a must-visit during the holiday season.

This brings the total to three Colorado towns on my list, but Vail is worth it. With twinkling lights lining the European-inspired architecture, cozy shops, and mountain views around every corner, visiting seemingly transports me to the scene of a movie.

I love the festive energy around the ice skating rink, where families and friends gather. Plus, I always have to stop by the Four Seasons for an elevated cup of "haute chocolate."

• Rob Reiner leaves a legacy on the big screen, thanks to classic movies like "When Harry Met Sally…" and "A Few Good Men."
• He and his wife died of an apparent homicide in their Los Angeles home on Sunday. He was 78.
• Here are the eight movies that define his career.

Rob Reiner leaves behind a body of work that won't soon be forgotten.

From comedies such as "When Harry Met Sally…" and "The Princess Bride" to classic Stephen King adaptations like "Stand by Me" and Misery," Reiner's storytelling mastery delivered some of the most memorable movies released in the 1980s and 1990s. And I didn't even mention the gripping drama "A Few Good Men."

Here are eight of Reiner's most memorable films.

"This Is Spinal Tap" (1984)

Being the son of Carl Reiner, a pioneer in onscreen comedy, and having acted in variety shows for most of his youth, eventually playing Michael "Meathead" Stivic on "All in the Family," throughout the 1970s, Reiner never had a problem being on screen.

It made him the perfect straight man opposite Christopher Guest, Michael McKean, and Harry Shearer in this comedy, which he also directed, about a fake band going on tour.

Essentially creating the mockumentary genre with the movie, Reiner plays a director named Marty Di Bergi who chronicles the US tour of the English rock band Spinal Tap.

The movie went on to become a cult classic. Guest has since taken the mockumentary reins, going on to create his own classics, such as the 2000 film "Best in Show" and the 2003 film "A Mighty Wind."

"Stand by Me" (1986)

Reiner adapted Stephen King's novella "The Body" for his sophomore directing effort and demonstrated that he can do much more than comedy.

This coming-of-age tale about a group of friends who set out to look for a dead body made stars out of its lead characters — Corey Feldman, Jerry O'Connell, River Phoenix, and Wil Wheaton — and decades later, you can find many similarities in the character development in Netflix's "Stranger Things."

"The Princess Bride" (1987)

Shifting to the fantasy genre, Reiner crafted a love story that has only grown in popularity.

Cary Elwes plays Westley, a swashbuckler determined to reconnect with his true love, played by Robin Wright, who is a princess set to be married.

Along the way, Elwes teams with the likes of Mandy Patinkin, Andre the Giant, and Billy Crystal to complete his quest.

"When Harry Met Sally…" (1989)

Reiner collaborated with screenwriter Nora Ephron to make one of the greatest romantic comedies ever.

From the fake orgasm in the diner scene to the romantic conclusion when Harry (Billy Crystal) finally professes his love to Sally (Meg Ryan) on New Year's Eve, any rom-com that has worked since is because it has used elements that originated in "When Harry Met Sally…."

"Misery" (1990)

A year later, Reiner would once more turn to Stephen King to prove he can do more than comedy.

James Caan plays a novelist who is held captive by an obsessive fan played by Kathy Bates.

The movie would be a sensation and lead to Bates winning an Oscar, marking the only time an Oscar has been awarded to a King adaptation.

"A Few Good Men" (1992)

Aaron Sorkin adapted his 1989 play for Reiner's next movie, which would go on to be nominated for four Oscars, including best picture.

With an all-star cast that includes Tom Cruise, Jack Nicholson, Demi Moore, Kevin Bacon, and Kiefer Sutherland, this courtroom drama focuses on a hotshot attorney (Cruise) trying to exonerate two Marines charged with the murder of another Marine.

The movie concludes with a showdown between Cruise and Nicholson, playing the Colonel at the base where the murder took place, that is highlighted by the now-famous movie line by Nicholson: "You can't handle the truth!"

"The American President" (1995)

Reiner and Sorkin would team up again for this lighthearted political drama, in which Michael Douglas plays a widowed President of the United States who falls for a lobbyist, played by Annette Bening.

The movie went on to be the spirit animal for Sorkin's beloved series "The West Wing," which aired from 1999 to 2006.

"Albert Brooks: Defending My Life" (2023)

One of Reiner's final directing efforts was this documentary on his good friend, Albert Brooks.

Reiner, who is also in a lot of the movie speaking with Brooks, recounts the comic's legendary career from being the go-to stand-up comic for Johnny Carson to becoming a renowned director himself ("Real Life," "Modern Romance," "Defending Your Life," "Mother").

• Rob Reiner and his wife, Michele, died on Sunday in an apparent homicide.
• This son, Nick, has been charged in connection with their deaths.
• In 2016, Business Insider interviewed Rob and Nick about their movie, "Being Charlie," which is based on Nick's past drug addiction.

Editor's note: Business Insider published an interview with Rob Reiner and his son Nick Reiner in May 2016 about their movie, "Being Charlie," which Nick wrote and is based on his experiences with drug addiction. On December 15, 2025, Nick Reiner was arrested one day after his parents, Rob Reiner and Michelle Singer Reiner, were found dead in their Los Angeles home.

For the last 30 years, Rob Reiner has been best known for directing movies like “Stand by Me,” “The Princess Bride,” “When Harry Met Sally,” and “A Few Good Men.” The titles have brought joy to millions.

But the Reiner household hasn't been all happy. The legendary actor/filmmaker’s son, Nick, 22, has been battling drug abuse since his late teens.

Most families would want to keep that part of their lives as hidden from public view as possible. But Reiner admits that, even at the darkest moments of his son’s addiction, he thought of making a movie. Yet it was too painful to put pen to page and begin a script.

Interestingly enough, his son came to the same realization as a means to rehabilitate.

While at a rehab center in Los Angeles four years ago, Nick befriended fellow addict Matt Elisofon. The two began writing about their challenges with addiction and the people they met at rehab. Eventually they came up with a script for the movie “Being Charlie” (in theaters Friday), which they asked Rob to direct.

The film had its world premiere at the Toronto International Film Festival last September to a sold-out crowd.

It’s a mix of drama and comedy that focuses on an 18-year-old named Charlie (played Nick Robinson of “Jurassic World” fame) as he struggles with addiction to heroin and cocaine. As Charlie jumps in and out of rehab, the aggravation of his actor-turned-politician father (Cary Elwes) grows, and he doesn’t know how to help his son.

“It was a real corrective emotional experience,” Nick Reiner told Business Insider following the TIFF screening about making the movie.

It took “Being Charlie” four years to get to the screen (in that time Nick has been sober), evolving from a half-hour comedy, then an hour dramedy that was rejected by the TV networks, to finally a feature film.

According to Rob Reiner, what the project lacked in its early development was telling both the father's and son's sides.

“It needed what he has been through but also what we had been through,” Rob told Business Insider, referring to himself and his wife, Michele, who was sitting beside him.

Nick and Elisofon were by Rob’s side throughout filming. According to Rob, the script was tweaked daily to make the scenes more true to life.

“I relied on him,” Rob said of his son. “He’s the heart and soul of the film.”

One of the biggest adjustments came while shooting the film’s ending, in which Charlie and his father finally have a heart-to-heart.

Rob and Nick couldn’t find the right tone. After constant rewrites, they finally felt they had something a few days before shooting the scene. It’s a gripping moment when both the father and son open up to each other like they never have before.

The Reiners compare getting the ending right to the whole experience making the film.

"We were healing as we were going along," Nick said. "And it all doesn’t happen overnight. Certain things we hadn’t dealt with for a while but we were able to through this movie. It didn’t fix everything, but it really tapped into — "

Nick paused to find the words, then his father, sitting across from Nick, finished for him.

"It forced me to really have to understand what he had been going through for a long time," Rob said.

This story was originally published on May 16, 2016. It has since been updated.

• Ukraine's long-range drones struck a Russian oil platform in the Caspian Sea, a security source said.
• It's the third time in a matter of days that Ukraine has attacked oil platforms in this area.
• The attacks mark a new chapter for Ukraine as it expands strikes on Russia's energy sector.

Ukraine has hit Russian oil platforms in the Caspian Sea with long-range drones three times in a matter of days, a security source told Business Insider on Monday.

In the most recent attack, drones struck a platform at the Korchagin oil and gas condensate field, causing damage at the facility and forcing it to halt production, said the source in the Security Service of Ukraine, who was only authorized to speak anonymously to discuss sensitive military developments.

The drone attack is the latest against Russia's energy sector, a critical source of income for Moscow that helps fuel its war efforts in Ukraine. Kyiv has ramped up its deep-strike campaign on key oil and gas facilities and is now targeting infrastructure in the Caspian Sea, hitting activities there for the third time in less than a week.

The source in the SBU, Ukraine's main internal security agency, said that drones struck the Filanovsky oil production platform last Thursday, marking the first time Kyiv had caused damage to Russian oil infrastructure in the Caspian Sea.

The following day, Ukrainian drones struck the Filanovsky platform again and also hit the Korchagin platform. The SBU source said that the attacks caused damage at both facilities and forced a suspension of operations.

The platforms are owned by Lukoil-Nizhnevolzhskneft, a subsidiary of the Russian energy giant Lukoil. The company did not immediately respond to a request for comment on the drone attacks. Additionally, neither Russia's defense ministry nor its US embassy responded to requests for comment.

The SBU source said that the agency is working to deny Russia the critical revenue from its energy sector, which helps finance the war in Ukraine. They said that the Filanovsky deposit is one of Russia's largest, with an estimated 129 million tons of oil.

"No Russian object working for the war is safe regardless of its location," the source said, according to a translation of their remarks shared with Business Insider.

The repeated targeting of the two Caspian Sea oil platforms appears to signal a new shift for Ukraine as it continues to strike Russian oil and gas infrastructure.

For months, Ukraine has mostly carried out attacks against oil refineries, ports, and other facilities across Russia. However, in recent weeks, Kyiv has expanded these operations beyond land and intensified its strikes on maritime targets.

Just before the three strikes in the Caspian Sea, Ukraine used its naval drones packed with explosives to attack three tankers allegedly belonging to the Russian "shadow fleet," a collection of hundreds of vessels that Moscow uses to move oil and circumvent sanctions on its energy exports.

Ukrainian officials have described the campaign against the Russian energy sector as "long-range" sanctions. The deep-strike campaign has been a bright spot for Kyiv in this war as Moscow's forces continue to make slow but costly gains on the battlefield.

Meanwhile, Ukraine has repeatedly urged its international partners to do more to prevent Russia from exporting oil and earning cash to fuel its invasion.

• Ukraine's internal security agency said it used an underwater drone to damage a Russian submarine.
• The agency described the attack as a first, potentially signaling a new chapter in drone warfare.
• Ukraine has long been using naval drones to target Russian surface ships.

Ukraine carried out a first-of-its-kind attack on a Russian submarine using underwater drones, Kyiv said on Monday, revealing a new use for its explosive-packed uncrewed systems.

The Security Service of Ukraine, or SBU, said it executed a "unique special operation" using an underwater drone to strike a Russian Kilo-class submarine at the Black Sea port Novorossiysk, damaging and disabling the boat.

The SBU, Ukraine's main internal security agency, disclosed that the attack involved the employment of its "Sub Sea Baby" drones, which appear to be an underwater version of the Sea Baby naval drone Ukraine uses to target Russian surface vessels and port infrastructure.

The SBU said in a statement that the submarine was equipped with four launchers for Kalibr cruise missiles, which Russia regularly fires at Ukrainian cities.

The security agency did not specify when the operation took place, but it said it was carried out in coordination with the Ukrainian navy. The SBU published footage that appears to show the moment the underwater drone impacted the submarine, causing a large explosion.

Neither Russia's defense ministry nor its US embassy immediately responded to requests for comment.

The Kilo-class submarines are diesel-electric boats that have been in service since the 1980s. Russia has dozens of active subs, which make up one of the largest submarine fleets in the world.

The SBU said a Kilo-class submarine costs around $400 million, but the agency added that sweeping international sanctions would make it notably more costly for Russia to build a replacement.

The submarine attack marks the latest against Russia's naval force in the Black Sea. Since the start of the war, Ukraine has employed drones and missiles to damage and destroy dozens of warships and other vessels.

The asymmetrical campaign has forced Russia to relocate the bulk of its battered Black Sea Fleet from the long-held headquarters on the occupied Crimean peninsula across the region to Novorossiysk. However, Ukraine has demonstrated it can target Russian ships there as well.

The SBU said on Monday that the damaged submarine was in Novorossiysk due to the Ukrainian operations that drove the Russian Navy away from Crimea earlier in the war.

More significantly, the submarine attack appears to signal a new chapter in drone warfare. Ukraine has used naval drones, such as the Sea Baby, to strike Russian surface ships and used underwater drones to target Russia's "shadow fleet" vessels moving oil and circumventing sanctions.

However, a strike on a submarine with what has been likened to a slow-moving mine or torpedo suggests an expansion of Ukrainian capabilities.

Beyond Ukraine, Russia and NATO countries have actively developed their own underwater drone technology as militaries look to augment traditional naval capabilities with more uncrewed systems.