Joe Biden says the Taliban promised to let Americans reach Kabul’s airport safely, but many evacuees are facing a treacherous journey. Sullivan said Monday the US military has “developed a method” to transport people to the airport, and while he didn’t offer specifics, hundreds of Americans were reportedly rescued via helicopter late last week.

However, a Taliban spokesperson ruled out an extension Monday, telling British broadcaster Sky News the group views Aug. 31 as a “red line” and foreign troops could “provoke a reaction” and face unspecified “consequences” if they stay beyond then.