Downing Street has hit back at Donald Trump’s defence secretary after he played down the role of British armed forces in the Afghanistan war.

Pete Hegseth suggested that “maybe five” other countries contributed to the war, with just “one or two” actually fighting in a renewed attack on Nato allies.

No 10 pushed back on the comments on Monday, saying “the facts speak for themselves” and that it is “wrong to diminish” the role of British troops.

“Look, frankly, the facts speak for themselves when it comes to the UK’s and Nato’s contribution to Afghanistan, thousands of British and allied families made huge sacrifices to play their significant parts in that war and uphold our values,” the prime minister’s spokesperson said.

“And more than 450 British personnel never returned. 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, and it is wrong to diminish their role.”

More than 1,100 non-US coalition fighters died in the conflict that began in 2001, according to veteran charity Help for Heroes, the overwhelming majority of them being from Nato countries, while more than 2,300 members of the US armed forces were killed.

The UK suffered the second-highest number of military deaths, behind the US.

Mr Hegseth was speaking to US army cadets about his time as a captain in Afghanistan.

“I was a captain in Afghanistan and we would go to the headquarters in Kabul and there would be 50 flags at the headquarters,” he said.

“It was a beautiful thing to see, 50 different countries contributing to the Nato alliance and the mission there. Except there were maybe five that contributed, it was actually closer to one or two that by the end were actually involved in kinetic operations.

“In fact the patch ‘ISAF’ – we joked it meant ‘I Saw Americans Fighting’.”

Earlier this year, President Trump was forced to climb down over his own false claims about Nato’s involvement in the war.

Asked about his suggestions that Nato would not support America if asked, 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.”

America remains the only country to have invoked the collective security provisions of Nato’s Article 5, with the alliance to provide support to the US after the terrorist attacks of September 11 2001.

He later paid tribute to “the great and very brave soldiers of the United Kingdom”, after his comments drew widespread outrage and the issue was raised directly to him by then-prime minister Sir Keir Starmer during a phone call.