India, Jan. 23 -- In his latest barb at European allies, US President Donald Trump on Thursday suggested that troops from other NATO countries stayed away from the frontline in Afghanistan in the 'War on Terror' after the 9/11 attacks.

"They'll say they sent some troops to Afghanistan," Trump said, referring to NATO allies, in an interview aired on Fox News on Thursday. "And they did; they stayed a little back, a little off the frontlines," he added.

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.

Trump questioned whether NATO would be there if the US ever needed them. "I've always said: will they be there if we ever need them? And that's rea...