Late Friday, U.S. Central Command Capt. Bill Urban said that the U.S. military carried out an unmanned airstrike in Afghanistan's Nangahar province targeting an "ISIS-K planner."

"Initial indications are that we killed the target. We know of no civilian casualties," Urban said in a statement.

The Pentagon said the airstrike was a retaliation for the deadly Kabul airport attack.

The president was warned Friday to expect another lethal attack in the closing days of a frantic U.S.-led evacuation. White House press secretary Jen Psaki said Biden's national security team offered a grim outlook.

"They advised the president and vice president that another terror attack in Kabul is likely, but that they are taking maximum force protection measures at the Kabul airport,” Psaki said, echoing what the Pentagon has been saying since the bombing Thursday at Kabul airport that pushed the White House deeper into crisis over a chaotic and deadly conclusion to a war that began nearly 20 years ago.

The State Department again urged Americans to stay away from airport gates, including “the New Ministry of Interior gate.”