The UK is in a race against time to help British nationals and supportive Afghans leave Afghanistan as the U.S. president suggested rescue missions must be completed within 10 days. President Joe Biden, at a press conference on Friday, signalled U.S. efforts to rescue American citizens could wrap up at the end of the month, a move that is likely to present a similar deadline for British armed and diplomatic attempts to get people out of the country after the Taliban took control. Asked whether the United States could get all Americans out of Afghanistan by Aug. 31, Biden told reporters: “I think we can get it done by then, but we’re going to make that judgment as we go.” It comes as Prime Minister Boris Johnson said the UK would have to “manage the consequences” of the U.S. withdrawal from the central Asian country, a move which has come …