Two top US military officials said they believed that a few thousand troops should have remained in Afghanistan and acknowledged other tactical and intelligence failings during the chaotic withdrawal of armed forces from the country.

During testimony before the Senate armed services committee on Tuesday, Mark Milley, chairman of the joint chiefs of staff, and Frank McKenzie, US commander of troops in the region, both made clear their personal views were at odds with the decision President Joe Biden took to withdraw all troops by his September 11 deadline.

“My view is that?2,500 was an appropriate number to remain, and if we went below that number in fact we would probably witness a collapse in the Afghan government and in the Afghan military,” McKenzie said in testimony, in comments echoed by Milley.