London, UK – President Donald Trump sparked outrage among allies with a suggestions that NATO troops had pulled out of fighting on the front lines in Afghanistan during the US invasion.

In an interview with Fox News aired on Thursday, Trump appeared unaware that 457 British soldiers died fighting in the South Asian country following the September 11 attacks.

"They'll say they sent some troops to Afghanistan," the Republican said. "And they did, they stayed a little back, a little off the front lines."

Trump also repeated his claim that NATO would not come to the aid of the US if asked to do so.

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In fact, following the 9/11 attacks, the UK and other allies joined the US from 2001 in Afghanistan after it invoked NATO's collective security clause.

As well as Britain's, troops from other NATO ally countries including Canada, France, Germany, Italy, and Denmark and others also died.

The UK's care minister, Stephen Kinnock, said he expected Prime Minister Keir Starmer to bring the issue up with Trump.

"I think he will, I'm sure, be raising this issue with the president... He's incredibly proud of our armed forces, and he will make that clear to the president," he told LBC Radio.

Trump's comments were "plainly wrong" and "deeply disappointing", Kinnock said on Sky News.

"It just doesn't really add up what he said, because the fact of the matter is the only time that article 5 has been invoked was to go to the aid of the United States after 9/11."

"And many, many British soldiers and many soldiers from other European NATO allies gave their lives in support of American missions, American-led missions in places like Afghanistan and Iraq," he added.

Lucy Aldridge, whose son William died aged 18 in Afghanistan, told The Mirror newspaper that Trump's remarks were "extremely upsetting".

Emily Thornberry, chair of parliament's Foreign Affairs Committee, called them "so much more than a mistake".

"It's an absolute insult. It's an insult to 457 families who lost someone in Afghanistan. How dare he say we weren't on the front line," the Labour Party politician said on the BBC's Question Time on Thursday evening.

According to official UK figures, 405 of the 457 British casualties who died in Afghanistan were killed in hostile military action. The US reportedly lost more than 2,400 soldiers.