Biden will travel to all three Sept. 11 sites in New York City, Pennsylvania, and Virginia, to mark 20th anniversary of the terrorist attacks

• President Biden and the first lady will travel to all three sites to honor the victims of 9/11.
• The Bidens will visit the WTC in Lower Manhattan, as well as Shanksville, Pa., and the Pentagon.
• This year marks the 20th anniversary of the terrorist attacks, which thoroughly reshaped the US.

President Joe Biden and first lady Jill Biden will commemorate the 20th anniversary of Sept. 11 terrorist attacks on Saturday by traveling to all three sites in New York City, Pennsylvania, and Virginia, the White House announced.

The president and the first lady will head to Lower Manhattan to pay tribute to the 2,763 victims of the World Trade Center collapses before heading to Shanksville, Pa., where 40 passengers and crew members on United Airlines Flight 93 perished after thwarting a planned attack on the US Capitol.

The Bidens will also visit the Pentagon, in Arlington, Va., to honor those killed after American Airlines Flight 77 crashed into the building after the plane was hijacked, taking the lives of 184 people - 125 in the government complex and 64 on the plane.

Nearly 3,000 people died on that solemn day in 2001.

Vice President Kamala Harris and second gentleman Douglas Emhoff will travel to Shanksville for a separate event that day and later meet the Bidens at the Pentagon.

On Saturday, the US will look back at one of the most consequential days in American history - as the attacks caused the government to reexamine domestic terror threats and led to the war in Afghanistan - and prepare for the myriad challenges ahead as the country continues to battle a deadly pandemic and face the consequences of the nearly 20-year Afghan conflict.

Biden oversaw a tumultuous August in Afghanistan - defined by the Aug. 15 fall of Kabul back to the Taliban, the deaths of 13 US service members and at least 169 Afghans in a Aug. 26 suicide bombing perpetuated by the Islamic State affiliate ISIS-K, and the Aug. 31 withdrawal deadline that the president chose to stand by despite vocal political opposition.

The troop withdrawal was carried out ahead of the original deadline of Sept. 11, 2021.

Biden on Friday signed an executive order allowing the Department of Justice and other agencies to conduct a declassification review of information related to the FBI's investigation of the Sept. 11 attacks. The issue had become a sticking point among relatives of loved ones who died in the attacks, with many family members telling the president not to attend memorial events if the documents were not declassified.

The order mandates that US Attorney General Merrick Garland release the documents publicly over the next six months.

"When I ran for president, I made a commitment to ensuring transparency regarding the declassification of documents on the September 11, 2001 terrorist attacks on America," Biden said in a statement. "My heart continues to be with the 9/11 families who are suffering, and my Administration will continue to engage respectfully with members of this community. I welcome their voices and insight as we chart a way forward."