President Barack Obama will attend a memorial service at the Pentagon on Saturday to mark the ninth anniversary of the Sept. 11 terrorist attacks, White House spokesman Robert Gibbs said Tuesday.

Vice President Joseph Biden will commemorate the day in New York, Gibbs said, while first lady Michelle Obama and former first lady Laura Bush will attend a ceremony in Shanksville, Pa., where one of the hijacked jets crashed.

The president attended a wreath-laying ceremony at the Pentagon on last year’s anniversary.