Biden to mark 20th anniversary of 9/11 at three memorial sites

President Joe Biden (Susan Walsh/AP)

President Joe Biden will visit all three 9/11 memorial sites to commemorate the 20th anniversary of the September 11 attacks and pay his respects to the nearly 3,000 people killed that day.

Mr Biden will visit ground zero in New York City, the Pentagon and the memorial outside Shanksville, Pennsylvania, where United Flight 93 was forced down, the White House said.