Nearly 1,800 Americans directly affected by the Sept. 11, 2001, terrorist attacks are opposing President Joe Biden's participation in any memorial events this year unless he upholds his pledge to declassify U.S. government evidence that they believe may show a link between Saudi Arabian leaders and the attacks. The victims' family members, first responders and survivors will release a statement Friday calling on Biden to skip 20th-anniversary events in New York and Shanksville, Pennsylvania, and at the Pentagon unless he releases the documents, which they believe implicate Saudi officials in supporting the acts of terrorism. The group says that ... Biden pledged to be more transparent and release as much information as possible but that his administration has since then ignored their letters. "We cannot in good faith, and with veneration to those lost, sick, and injured, welcome the president to our hallowed grounds until he fulfills his commitment," they wrote in a statement. "Since the conclusion of the 9/11 Commission in 2004 much investigative evidence has been uncovered implicating Saudi government officials in supporting the attacks," the statement says. "The Department of Justice and the FBI have actively sought to keep this information secret and prevent the American people from learning the full truth about the 9/11 attacks." The administrations of George W. Bush, Barack Obama and Donald Trump also declined to declassify supporting documents.