NEW YORK >> President Joe Biden, Vice President Kamala Harris and former President Donald Trump made a rare joint appearance on Wednesday at the New York City site that marks the Sept. 11 plane attacks in 2001 that killed nearly 3,000 people.

Harris, the Democratic presidential candidate and Trump, her Republican rival in the Nov. 5 U.S. presidential election, shook hands and exchanged a few words despite their contentious debate the night before, then lined up for the commemoration. Trump’s running mate, Senator JD Vance, also attended.

There were no formal remarks at the “ground zero” site where planes brought down the World Trade Center’s twin towers. Instead, wives, husbands, sisters, brothers and grandchildren read out the names of family members killed 23 years ago.

The annual rite marks the suicide attacks by al Qaeda Islamist militants who flew two planes into the World Trade Center and another into the Pentagon. A fourth plane went down in a Pennsylvania field after passengers stormed the cockpit.

“Richard J. O’Connor. We will always love and miss you,” a red-headed boy said of his grandfather, who was killed at the World Trade Center.

A bagpipe and drum processional was accompanied by New York City’s fire and police departments and Port Authority honor guards. The national anthem was performed and moments of silence were held at the times each target was struck.

After New York, Biden and Harris flew to Shanksville, Pennsylvania, where passengers on United Flight 93 overcame the hijackers and the plane crashed in a field, preventing another target from being hit.

At a white marble memorial in the field, Biden gently laid a hand on the wreath to pay his respects to the 40 people killed in the crash. He and Harris were joined by Calvin Wilson, the brother-in-law of Flight 93 co-pilot LeRoy Homer Jr.

The president and vice president spoke with local fire officials at the Shanksville Volunteer Fire Department, pausing for a moment to observe another memorial, erected on an adjacent hill where 40 flags waved in the wind.

There, Biden spoke about the need for the country to return to bipartisan unity and gave a hat to a Trump supporter, who gave him a Trump hat in return, according to spokesperson Andrew Bates.

Biden wore the hat, making for a viral photograph. “Thanks for the support, Joe,” the Trump campaign wrote on social media.

Biden and Harris later headed to a memorial at the Pentagon. There, they carried a wreath decorated in red, white and blue, bowed their heads and stood before it for a few moments before “Taps” played.

“On this day 23 years ago, terrorists believed they could break our will and bring us to our knees. They were wrong. They will always be wrong. In the darkest of hours, we found light. And in the face of fear, we came together – to defend our country, and to help one another,” Biden said in a statement.

Trump, who visited the Pennsylvania memorial on Wednesday, told Fox News: “It was very, very sad, horrible day. There’s never been anything like it.”

Biden earlier issued a proclamation honoring those who died as a result of the attacks, as well as the hundreds of thousands of Americans who volunteered for military service afterward.

“We owe these patriots of the 9/11 Generation a debt of gratitude that we can never fully repay,” Biden said, citing deployments to Afghanistan, Iraq and other war zones, as well as the capture and killing of Sept. 11 mastermind Osama bin Laden.

Additional reporting by Susan Heavey and Helen Coster.