Osama bin Laden's killing was an "act of national self-defense," Attorney General Eric Holder said Wednesday. 

"It was justified as an act of national self-defense," Holder said Wednesday at a Senate Judiciary Committee hearing. "If he had surrendered, attempted to surrender, I think we should obviously have accepted that, but there was no indication that he wanted to do that, and therefore his killing was appropriate."

Initially, the Obama administration said bin Laden had been armed and resisting U.S. forces when they stormed his compound Sunday. On Tuesday, White House press secretary Jay Carney said the more complete story was that bin Laden had been unarmed but was resisting the soldiers. 

Even as the story has changed, the White House has stuck to its assertion that bin Laden left the soldiers no choice but to shoot at him. 

"Resistance does not require a firearm," Carney said Tuesday.