Biden's remarks about national unity on the 21st anniversary of the attacks stood in contrast to his warnings in recent days about dangerous divisions in American society, including that some Republicans who support former President Donald Trump's agenda pose a threat to democracy.
"I hope we'll remember that in the midst of these dark days, we dug deep. We cared for each other. And we came together," Biden said, as rain fell on troops standing behind him, flanking his defense secretary and top general.
Nearly 3,000 people died in the attacks, when al Qaeda hijackers flew planes into the New York's World Trade Center towers and into the Pentagon in Arlington, Virginia, while a fourth plane crashed in Pennsylvania.
Passengers on United Airlines Flight 93 overcame the hijackers and the plane crashed in that Pennsylvania field, preventing another target from being hit
Biden's remarks about national unity on the 21st anniversary of the attacks stood in contrast to his warnings in recent days about dangerous divisions in American society, including that some Republicans who support former President Donald Trump's agenda pose a threat to democracy.
Passengers on United Airlines Flight 93 overcame the hijackers and the plane crashed in a field, preventing another target from being hit.
The anniversary comes a year after Biden ended the U.S.-led war in Afghanistan, launched two decades ago to root out the al Qaeda militant group that carried out the 9/11 attacks after plotting them from Afghanistan.