Bush turned down the invitation, Politico reported. A source suggested he does not want to take away from Obama's moment as the president who ordered the assassination of Osama bin Laden.
Obama called Bush before the public announcement Sunday that bin Laden had been killed at his compound in Pakistan. Bush, a Republican, released a statement praising the Democratic president.
Giuliani, who has not yet said whether he will attend, has also credited Obama. A number of Republicans, including former Alaska Gov. Sarah Palin, who spoke Monday at Colorado Christian University, have pointedly praised Bush while not mentioning Obama, the Los Angeles Times reported.
The current New York mayor, Michael Bloomberg, spoke Monday at the World Trade Center site.