(CNN) -- The US has conducted an airstrike against an ISIS-K planner, a spokesman for US Central Command said in a statement Friday.
"U.S. military forces conducted an over-the-horizon counterterrorism operation today against an ISIS-K planner. The unmanned airstrike occurred in the Nangahar Province of Afghanistan. Initial indications are that we killed the target. We know of no civilian casualties," spokesman Capt. Bill Urban said in the statement.
The announcement of the strike came a day after President Joe Biden vowed to retaliate for a terrorist attack that killed 13 US service members and at least 170 others outside Kabul's international airport even as he said the frantic mission to airlift Americans from Afghanistan would continue.
Biden approved the strike on the ISIS-K planner, according to an official familiar with the matter.
White House press secretary Jen Psaki said in a statement earlier Friday that Biden and Vice President Kamala Harris had been warned by their national security team that "another terror attack in Kabul is likely."
The US Embassy in Kabul again advised US citizens at a number of gates at the airport to "leave immediately," citing security threats.
"Because of security threats at the Kabul airport, we continue to advise U.S. citizens to avoid traveling to the airport and to avoid airport gates," the alert said.