President Joe Biden vowed to retaliate against an ISIS affiliate following its deadly attack at the Kabul airport that killed a dozen Americans along with scores of Afghans.

Addressing the nation from the White House on Thursday, Aug. 26, Biden said the United States would find those behind the terror attack and hold them responsible.

“To those that carried out this attack, as well as anyone who wishes America harm, know this: We will not forgive. We will not forget. We will hunt you down and make you pay,” he said.

At least 12 U.S. service members and 60 Afghans were killed after two suicide bombers, and gunmen attacked crowds of Afghans flocking to Hamid Karzai International Airport, The Associated Press reported, citing Afghan and U.S. officials.

The Islamic State affiliate in Afghanistan, known as the Islamic State-Khorasan Province, or ISIS-K, said that it targeted American troops and Afghan allies in its claim of responsibility.

The attack comes as the Biden administration has been withdrawing American forces from Afghanistan after the 20-year war.

In his speech, Biden held a moment of silence for the Kabul victims, which include 11 Marines and one Navy medic.

“These American service members who gave their lives—It’s an overused word, but it’s totally appropriate here—were heroes,” he said, adding that they were “engaged in a dangerous, selfless mission to save the lives of others.”

Thousands of Afghan people have crowded in for nearly two weeks at the Kabul airport in hopes of an evacuation, and U.S. service members had been carrying out screenings at the gates of the airport.

Biden vowed that the mission to evacuate Americans and Afghans would continue. 

“We will not be deterred by terrorists. We will not let them stop our mission. We will continue the evacuation,” he said.