The KC-135 plane went down in western Iraq at around 2pm on 12 March, US Central Command (CENTCOM), which oversees US military operations in the Middle East, said in a statement on Friday.
The identities of the dead service members are being withheld for 24 hours after next of kin have been notified.
The plane crash "was not due to hostile fire or friendly fire", CENTCOM said, echoing an earlier statement on the incident which involved another aircraft that landed safely.
A US official, speaking on condition of anonymity, told the Reuters news agency the other aircraft was also a KC-135 refuelling plane.
The circumstances of the incident were under investigation, CENTCOM added.
An umbrella group of Iranian proxies called the Islamic Resistance in Iraq claimed responsibility for downing the plane on Thursday. But the group previously made false claims about attacks during the Iran war.
The US military has used the KC-135, built by Boeing in the 1950s and early 1960s, for more than 60 years to refuel aircraft mid-flight, allowing them to carry out missions without having to land.
Read more from Sky News:
Oil tankers to be escorted through Strait of Hormuz
What we know about the deadly Iran school strike
Seven US troops - 13 when the crew members from the crashed plane are taken into account - have been killed since the start of the US-Israeli strikes on Iran on 28 February.
So far, the war has killed more than 2,000 people, including nearly 700 in Lebanon. Israel has expanded its offensive against Iran-backed Hezbollah, with strikes hitting Lebanon's capital Beirut overnight.
It's brought a spike in oil prices, a chance to play peacemaker, and now the easing of US sanctions on Russian oil.
This latest development marks a stunning reversal of policy from the Trump administration, and a major coup for the Kremlin.
Iran war latest: Explosion reported near Tehran march
Scott Bessent, the US treasury secretary, has played down the significance of any financial benefits for Moscow, stressing that the measures are "narrowly tailored" and "short term".
But that feels like wishful thinking from Washington, and a lot of positive spin.
According to the Financial Times, Russia has been pocketing as much as $150m a day in extra oil revenues as a result of the crisis, after the disruption to global energy supplies led to increased demand from China and India.
The lifting of sanctions means it now has a load of extra customers it can potentially sell to, and business has already begun, with Thailand announcing this morning that it's ready to buy Russian oil.
Oil was the area where the Trump administration had sought to put pressure on the Kremlin - to harm its economy in a bid to bring it to the table on Ukraine.
To a certain extent it was working. Depleted sales to India (as a result of US sanctions), combined with a drop in prices, has led to a ballooning budget deficit, by depriving the Kremlin of a vital source of income.
Russia's defence spending hadn't been impacted yet, but it was making the maths harder for Moscow to add up.
So this represents a remarkable turnaround, not only economically but diplomatically too.
Read more:
Why Trump's war with Iran will help fund Russia's assault on Ukraine
US Navy to escort oil tankers through Strait of Hormuz
Symbolically it brings Russian oil back in from the cold, and creates further splits in the transatlantic alliance.
Europe is staunchly against any sanctions relief for Russia, with both Ursula von der Leyen and German Chancellor Friedrich Merz voicing their opposition to it in recent days. Such friction only plays into Moscow's hands.
Domestically, too, it helps the Kremlin reinforce its message to the public that it was right all along - that the world needs Russia.
"The US is effectively acknowledging the obvious: without Russian oil, the global energy market cannot remain stable," Kremlin investment envoy Kirill Dmitriev wrote on Telegram.
"Amid the growing energy crisis, further easing of restrictions on Russian energy sources appears increasingly inevitable, despite resistance from some in the Brussels bureaucracy," he added.
Moscow clearly hopes this means that the sanctions genie is out of the bottle. Depending on the direction of oil prices, it may well be right.
The big honours started with a Critics Choice award in January. A Golden Globe followed, then a BAFTA, and most recently, a statuette at the Actor Awards.
Buckley is the only acting nominee to take home all four this year, and she has picked up other smaller awards, too. The Oscar, it seems, is hers to lose.
Gold Derby, the LA based authority when it comes to awards predictions, rates her chance of winning at an almost unbeatable 97%. "It's really been a crazy award season, it's been pretty unprecedented," says Debra Birnbaum, the site's editor-in-chief. But Buckley, she says, "is a sure thing... a pretty safe bet".
If Buckley does win, she will make history - the first Irish actress ever to take home the award.
The 36-year-old is being recognised for her portrayal of Agnes, the wife of Shakespeare in Chloe Zhao's Hamnet. The film chronicles the couple's grief following the death of their young son, and puts the bard, played by Paul Mescal, in the backseat as Agnes's story takes centre stage. Buckley's raw, emotive performance has moved audiences to tears.
In a sea of A-list Oscar nominees, including two-time winner Emma Stone, critics have singled her out as "one of the finest actresses of her generation".
"To be in a room with all those incredible artists, that, for me, is the greatest thing," Buckley told Sky News last month, speaking about her awards and nominations. "That and being a mom."
The actress gave birth to her first child, a girl, last year, and she has paid tribute to her in her speeches so far. "I'd like to share this with my daughter," she said of her BAFTA. "I promise to continue to be disobedient so that you can belong to a world in all your mad, complex wildness as a young woman."
This is Buckley's second Oscar nomination; her first was for best supporting actress, for her performance in The Lost Daughter, starring Olivia Colman, in 2022. She has also starred in other Oscar-nominated films, such as Women Talking, alongside Rooney Mara and Claire Foy, and Judy, opposite Renee Zellweger, and won several awards for her leading performance in the West End revival of Cabaret.
But she has been quietly honing her talents since she was young, growing up in Killarney, Co Kerry. Her rise to fame came when she was a teenager, appearing on the BBC reality show I'd Do Anything, which sought to find an unknown lead to play Nancy in the West End revival of the musical Oliver!, in 2008.
Buckley came second, but continued to pursue her love for the stage and screen. She went on to appear in series including Taboo and The Last Post, before breakout roles in British films Beast and Wild Rose, and the critically acclaimed HBO/ Sky series Chernobyl.
Back in 2019, when Wild Rose was released, Buckley said she grew up without a TV at home until she was "about eight or nine", and that her first experience of wanting to act was watching a "Vincente Minnelli and Judy Garland film... it was like my mind had been exploded into kind of like magic".
Now, not only has she reached the highest accolades for her achievements on screen, but she is also a Mercury Prize nominee, too - shortlisted in 2022 for her collaborative album For All Our Days That Tear The Heart, with former Suede guitarist Bernard Butler.
'You couldn't take your eyes off her'
For those who knew her at the Ursuline Secondary School, in Co Tipperary, her success has come as no surprise. Music teacher Joan Butler, who joined the school in 2006, Buckley's final year, says it was clear she would go on to big things.
"We're so proud of all our students here, but Jessie stood out… even as she began along her career path, as being somebody with a very special talent," she says. "She was in a production of West Side Story in my first year teaching… Spellbinding is the word we use here as we've been talking about her and remembering her time here.
"You couldn't take your eyes off Jessie on the stage or when she was singing or even at the piano. It's a star quality that is very, very rare. I can still remember I was playing violin in the pit orchestra, looking up the stage... the whole room just stopped, mouths open, watching this rehearsal. And I remember turning to some of the students and going, watch her girls, she's going to win an Oscar one day."
Now, Buckley could very well achieve that dream.
After seeing the actress tackling such physically and emotionally demanding scenes during the filming of Hamnet, her cast and crewmates say it has been incredible to see her hard work and talent recognised.
Hamnet set decorator Alice Felton, who is also up for an Oscar herself, nominated in the production design category, says they have "all been in tears" watching Buckley receive her awards.
"Because we watched her throughout filming give her heart and soul to that," she says. "We'd be crying at the edge of set before the music was laid in, before everything was done.
"She's a beautiful person. She gave everything to that role and she's part of the team. She used to sleep in the bed in the attic [in their house in the film]. So I'd go up to redress the set and she'd be tucked up having a little nap. She just lived in the spaces and we're all so happy for her."
Irish stars show support in LA
In Los Angeles in the days leading up to the Oscars ceremony each year, the US-Ireland Alliance hosts the Oscar Wilde Awards, celebrating Irish talent.
They have had a lot to toast in recent years, including nine nominations for The Banshees Of Inisherin (starring another former Ursuline pupil, Kerry Condon) in 2023. And in 2024, Cillian Murphy became the first Irish star to win best actor, for his performance in Oppenheimer.
Read more:
Warner Bros looks set for Oscars success amid takeover plans
One Battle After Another is 'devastatingly timely'
Oscars - iconic looks that broke the rules
This year, Buckley is the person everyone is talking about.
Gleeson, who starred alongside her in the animated Christmas special The Scarecrows' Wedding, told Sky News: "We're already celebrating Jessie Buckley.
"She is an absolutely amazing actor. She's so incredible in the film and I'll be delighted, delighted if she wins. But we celebrate her all the time."
Singer-songwriter Dermot Kennedy also highlighted Buckley's musical talents. "I think people are largely unaware of how great a singer she is," he said. "She's just an incredibly talented person, so we're very excited for her."
And speaking at the premiere of the Peaky Blinders film earlier this month, Murphy himself showed his support. "She's incredible," he told Sky News. "I'm just so happy for her, she's unbelievable in that film."
For the young students at Ursuline hoping to follow in Buckley's footsteps, the actress is an inspiration.
"We are so excited to see everything that will come after this as well," Ms Butler says. "Thank you so much to her for everything that she has done in inspiring our students and showing them what can be possible."
Madeleine Lonsdale, 18, had been racing another car at 100mph before she struck a tree in Marston, Lincolnshire, on 20 June last year, killing passengers Harrison Carter, 18, and George Stephenson, 17.
She partied "repeatedly" in the months after their deaths, frequently uploaded to TikTok and her first court appearance was delayed for two weeks because she went on a skiing trip.
On Friday she was sentenced to 14 months behind bars, having earlier pleaded guilty to two counts of causing the teenagers' deaths by careless or inconsiderate driving.
Mr Carter and Mr Stephenson had been passengers in Lonsdale's Kia Niro when the three headed to an Esso petrol station off the A1 in the early hours of the morning.
The car was travelling at 76mph when Lonsdale misjudged a bend in the 60mph road, killing both passengers almost immediately.
Lonsdale, who passed her driving test about 12 weeks before the crash, escaped with just a small injury to her wrist.
Moments earlier, Lonsdale had been racing another friend on the A1 - briefly travelling at 100mph, the court heard.
Sarah Carter said of her son, who wanted to pursue a career in law: "Harry was taken from us because Madeleine chose to speed.
"He will never be able to celebrate the amazing exam results that he achieved."
Ms Carter said it "adds insult to injury" that Lonsdale was "partying repeatedly" and "choreographing TikToks" while she planned her son's funeral.
Victoria Stephenson, George's mother, told the court: "We will never see him graduate or find a job after university.
"We didn't get to celebrate his 18th birthday with him. Instead, we had his funeral."
She said that when Lonsdale went on a skiing trip, delaying her first court appearance by two weeks, it "only added to the torment".
Read more from Sky News:
Boy dies after being struck by car
Epping council loses bid to stop housing asylum seekers at hotel
John McNally, defending Lonsdale, said: "She knows that there is nothing she can say, do, to take the pain away.
"She knows it will weigh heavily on her for the rest of her life.
"Her regret for what happened is deep and … her friends will remain, and are, in her thoughts."
Lonsdale was disqualified from driving for three years.
The 12-year-old Envoi Allen collapsed and died after finishing ninth in the festival's flagship race, the Boodles Cheltenham Gold Cup.
His owners, Cheveley Park Stud, had previously confirmed that he would have retired following his run in the blue riband, his eighth career appearance at the festival.
Over the course of his life, Envoi Allen won 10 Grade Ones races in total, having started out with the stable of Gordon Elliott, before moving to trainer Henry de Bromhead.
HMS Seahorse and Hansard were the two other horses that died at this year's Cheltenham festival.
In a statement after the death of the second horse, animal charity RSPCA said: "Lessons must be learned from tragedies like this - around the contributing factors, pre-and mid-race decision-making, and means of prevention".
Read more from Sky News:
All crew members killed in US refuelling plane crash in Iraq
Formula 1 races in Bahrain and Saudi Arabia set to be cancelled
The British Horseracing Authority (BHA) has not released any information about the deaths on its website.
However, the group did announce yesterday that it would launch a review into the starts of races at Cheltenham, following a series of false starts.