WASHINGTON (AP) President Joe Biden marked the 21st anniversary of the Sept. 11 attacks , taking part in a somber wreath-laying ceremony at the Pentagon held under a steady rain and paying tribute to extraordinary Americans who gave their lives on one of the nations darkest days.

Sundays ceremony occurred a little more than a year after Biden ended the long and costly war in Afghanistan that the U.S. and allies launched in response to the terror attacks.

Biden noted that even after the United States left Afghanistan that his administration continues to pursue those responsible for the 9/11 attacks. Last month, Biden announced the U.S. had killed Ayman al-Zawahri , the al-Qaida leader who helped plot the Sept. 11 attacks, in a clandestine operation.

We will never forget, we will never give up, Biden said. Our commitment to preventing another attack on the United States is without end.

The president was joined by family members of the fallen, first responders who had been at the Pentagon on the day of the attack, as well as Defense Department leadership for the annual moment of tribute carried out in New York City, the Pentagon and Somerset County, Pennsylvania.