The United States should extend the May 1 deadline for pulling all its troops from Afghanistan, and make force cuts contingent on progress in peace talks as well as by the Taliban in reducing violence and containing al Qaeda, a bipartisan report to Congress said on Wednesday.

Washington should not abandon the Afghan peace process, the report said. But conditions for its success will not be met by a May 1 deadline set in a 2020 US-Taliban agreement. Withdrawing all US troops then could lead to civil war, destabilising the region and reviving the al Qaeda threat.

The United States "should not...simply hand a victory to the Taliban," said the Afghanistan Study Group report, reflecting criticism that the Trump administration conceded too much to the insurgents in a bid to...