U.S. urges Americans to leave Kabul's airport due to "credible threat"

• Taliban security forces closed off Kabul’s airport to most Afghans seeking to evacuate Saturday, as the U.S. and its allies were wrapping up a "chaotic airlift," per AP.
• Biden said in a statement earlier Saturday that the situation on the ground "continues to be extremely dangerous, and the threat of terrorist attacks on the airport remains high."

Of note: The U.S. Embassy had warned American citizens late Friday that due to continued security threats, they should "avoid traveling" to Kabul's airport and "to avoid airport gates."

• "U.S. citizens who are at the Abbey gate, East gate, North gate or the New Ministry of Interior gate now should leave immediately," the notice warned.

The big picture: Biden's remarks came after the Department of Defense announced on Saturday that U.S. forces had begun to drawdown ahead of the Aug. 31 withdrawal deadline.

• "We have begun retrograding," Pentagon spokesperson John Kirby told reporters during a press briefing.

• The United Kingdom’s final flight for civilians departed Saturday.
• "It’s time to close this phase of the operation now," U.K. Ambassador Laurie Bristow said in a video message. "But we haven't forgotten the people who still need to leave and will continue to do everything we can to help them."

Go deeper: The Afghan refugee crisis is about to get much worse

Editor's note: This article has been updated with details of the U.S. Embassy's new warning and to reflect that the Taliban has closed off Kabul's airport to most Afghans.