Biden visits all three sites of 9/11 attack

U.S. President Joe Biden commemorated the 20th anniversary of the Sept. 11 attacks on Saturday with visits to each of the sites where hijacked planes crashed in 2001, honoring the victims of the devastating assault.

In the first of his wordless tributes, Biden stood in somber silence with former Presidents Barack Obama and Bill Clinton at the New York City site where planes brought down the World Trade Center's twin towers.

The three leaders, flanked by Jill Biden, Michelle Obama and Hillary Clinton, shared a moment of silence with the crowd at 8:46 a.m. to mark the time that the first plane hit.

Heads bowed, they listened as relatives read the names of those who died.

The Bidens then flew to Shanksville, Pennsylvania , where they participated in a wreath-laying ceremony at the Flight 93 National Memorial.

Also in Shanksville, former President George W. Bush, who led the country at the time of the attacks, in rare public comments, warned of the threat of domestic terrorism.

"There is little cultural overlaps between violent extremists abroad and violent extremists at home ... they are children of the same foul spirit, and it is our continuing duty to confront them."

He also called for the kind of unity he witnessed following the attacks.

But back in New York...that call for unity was not part of former President Donald Trump's remarks. Trump didn't attend any formal events, but spoke to a group of New York police officers at a precinct near Trump Tower to air his grievances and repeat his false claims of election fraud.

"We have a rigged election..."

He also attacked President Biden for his handling of the withdrawal of American troops from Afghanistan.

Biden: "These memorial are really important, but they're also incredibly difficult for the people affected by them."

Biden in Pennsylvania spoke to reporters on a range of issues, praising Bush's call for unity, defending his Afghanistan pullout and hailing the bravery of the passengers and crew of Flight 93.

"That's genuine heroism."

Later in the day he visited the Pentagon to honor those lost in the attacks.