US President Donald Trump has drawn sharp criticism in Britain after remarks widely seen as downplaying the role of UK forces in the Afghanistan war, prompting an unusually swift and forceful rebuke from Downing Street.

Prime Minister Keir Starmer accused Trump of “diminishing” the service and sacrifice of British troops by suggesting that NATO allies “stayed a little back, a little off the front lines” during the conflict. The comments have reopened tensions between London and Washington at a sensitive moment in transatlantic relations.

A Downing Street spokesperson said: “The President was wrong to diminish the role of NATO troops, including British forces, in Afghanistan. Following the 9/11 attacks on the US, Article 5 of the NATO treaty was invoked for the first time, and British forces served alongside American and other allied troops in sustained combat operations.”

The spokesperson added that 457 British service personnel were killed during the war, with many more wounded. “Many hundreds suffered life-changing injuries from their service alongside the US and our allies in Afghanistan. Their sacrifice, and that of other NATO forces, was made in the service of collective security and in response to an attack on our ally. We are incredibly proud of our armed forces and their service and sacrifice will never be forgotten.”

Defence Minister Al Carns, a former Royal Marines commando who served multiple tours in Afghanistan, described Trump’s remarks as “ridiculous.” “I served five tours in Afghanistan, many alongside my American colleagues. We shed blood, sweat and tears together. Not everybody came home,” he said. “These are bonds forged in fire… protecting democracy overall.”

Defence Secretary John Healey also condemned the comments, saying British troops should be remembered “for who they were: heroes who gave their lives in service of our nation.”

Trump made the remarks while reiterating his belief that NATO allies would not stand by the United States in a future crisis. In a television interview, he said: “We’ve never needed them. They’ll say they sent some troops to Afghanistan… and they did, they stayed a little back, a little off the front lines.”

The Afghanistan campaign followed the invocation of NATO’s Article 5 after the September 11, 2001 attacks, the only time the collective defence clause has been activated. British forces fought alongside US and allied troops throughout the conflict, often in some of the most dangerous regions.

Political figures across the UK condemned Trump’s comments. Conservative leader Kemi Badenoch called them “flat-out nonsense,” adding: “This is a fact, not opinion. Their sacrifice deserves respect, not denigration.” Diane Dernie, whose son Ben Parkinson is one of the most severely wounded British soldiers to survive the war, described the remarks as the “ultimate insult.”

Former cabinet secretary Lord Sedwill, who served as Britain’s ambassador to Afghanistan, said: “The US carried a huge share and UK and Danish forces also took heavy casualties in some of the hardest areas. Any suggestion otherwise is simply wrong and deeply offensive to veterans and families of those who died.”

The episode marks another flashpoint in relations between the UK and the Trump administration, as European allies continue to push back against rhetoric they see as undermining shared military history and alliance solidarity.