WATCH: Jen Psaki gives White House news briefing following explosions outside Kabul airport

White House press secretary Jen Psaki said Thursday U.S. flags across the country will be flown at half-staff until August 30th to mark the loss of life to U.S. service personnel due to a bombing at the Kabul airport Thursday.

Watch Psaki’s remarks in the player above.

The attacks killed at least 60 Afghans and 13 U.S. troops, Afghan and U.S. officials said.

The blasts came hours after Western officials warned of a major attack, urging people to leave the airport.

But that advice went largely unheeded by Afghans desperate to escape the country in the last few days of an American-led evacuation before the U.S. officially ends its 20-year presence on Aug. 31.

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The Islamic State group claimed responsibility for the killings on its Amaq news channel.

Psaki said the U.S. has no information that the Taliban was aware ahead of time, or took part, in the attack.

“Obviously, what happened today, and the loss of lives of U.S. service members of Afghans, is a tragedy, is horrific, is one of the worst things, if not the worst thing we have experienced during President Biden’s time in office.”

She also said President Biden plans to finish the mission at the Kabul airport on August 31st, is based on the advice of his military commanders.