US Defence Secretary Lloyd Austin told Congress on Thursday that America’s troop withdrawal from Afghanistan is “slightly” ahead of schedule. But Mr Austin did not say whether the Pentagon is on track to beat the September 11 deadline. President Joe Biden has ordered a full US troop withdrawal from Afghanistan by that date, which marks 20 years since the 9-11 attacks that prompted the American-led invasion of the country and the start of its longest war. Mr Austin told a House appropriations subcommittee hearing that the Defence Department’s proposed $715 billion budget would include money to help the military develop ways to prevent attacks against the US by terrorist groups in Afghanistan. With the budget set to be released on Friday, he provided few specifics to committee members asking about spending priorities. US commanders have said they will monitor and counter threats from Al Qaeda and ISIS from outside Afghanistan after US forces leave. Militants are expected to try to regroup after US and coalition troops depart. So far, officials have acknowledged that the US does not yet have any agreements for bases or to use airspace with any of the countries neighbouring Afghanistan.