US president Barack Obama and first lady Michelle Obama will attend events in New York City, Pennsylvania and Washington next month to mark the 10th anniversary of the 9/11 terrorist attacks.
The attacks killed nearly 3,000 people at the World Trade Centre in lower Manhattan, at the Pentagon and near Shanksville, Pennsylvania.
Spokesman Jay Carney said Mr Obama would pay tribute to those who died and would also honour those who responded on September 11, 2001, and who have served in harm’s way in the decade since then.
His vice president Joe Biden will help dedicate a memorial at Shanksville to the passengers of Flight 93 on September 10.
That United Airlines flight crashed in a south-western Pennsylvania field after passengers confronted their terrorist hijackers.