US officials were concerned that Pakistan could jeopardize the Osama bin Laden operation and "might alert the targets," if Islamabad took part in the mission, Leon Panetta, the CIA director, has said.
In an interview with Time magazine published on Tuesday, Panetta said US forces had gathered an "impressive amount" of material in Sunday's raid, including computers and electronics.
Panetta said the CIA had ruled out working with Pakistan on the raid because "it was decided that any effort to work with the Pakistanis could jeopardize the mission: They might alert the targets".
He said his aides had 60 to 80 per cent confidence that bin Laden was in the compound in Abbottabad, a town about two hours north of Islamabad, the capital.
Pakistan on Tuesday denied any prior knowledge of the US raid that killed bin Laden, but said it had been sharing information about the targeted compound with the CIA since 2009.