The Obama administration has seen no evidence Pakistan's leadership knew Osama bin Laden was living in that country before his killing last week by U.S. forces, the U.S. national security adviser said on Sunday.
"I can tell you directly that -- I've not seen evidence that would tell us that the political, the military, or the intelligence leadership had foreknowledge -- of bin Laden," Tom Donilon told NBC's "Meet the Press" when asked if Pakistan was guilty of harbouring the al Qaeda leader.
But he added bin Laden's residence for several years inside a compound in Abbottabad, 35 miles (56 km) north of the capital, Islamabad, "needs to be investigated.
"The Pakistanis have said they're going to investigate," Donilon said. "This is a very big issue in Pakistan right now. How could this have happened in Pakistan? We need to investigate it. We need to work with the Pakistanis. And we're pressing the Pakistanis on this investigation."
Donilon, who appeared on a number of Sunday talk shows, told CNN's "State of the Union" that he expected cooperation from Pakistanis.
"We would expect to have access to the things that we need," he said,.
Donilon said Pakistani officials also needed to provide U.S. authorities with intelligence they had gathered from the compound where bin Laden was killed, including access to bin Laden's three wives who are in Pakistani custody.
A senior U.S. official told NBC News that threat information from the bin Laden compound files already have been turned over to countries who are allies of the U.S.
"We have absolutely turned over threat info to other countries as we have found it in the files ... and we have already found some," the official said. The official would not identify which countries or provide details on the threat information.
Former Vice President Dick Cheney told "Fox News Sunday" that it was important for the United States to maintain good relations with Pakistan.
"I have questions, I'd like to know more about it," Cheney said about bin Laden's presence in Pakistan. "But I also think it's important for us to remember we have a broad range of issues that we work with Pakistan together."
Senate Foreign Relations Committee Chairman John Kerry said he also wanted to know how much Pakistan knew.
"It's extraordinarily hard to believe that he could have survived there for five years or more in a major population centre without some kind of support system and knowledge," Kerry told CBS's "Face the Nation."
Donilon said that despite difficulties in the relationship, Pakistan is an important partner for the United States.
"We have had our problems with Pakistan but we have also had a tremendous amount of partnership and cooperation with them in our effort in terrorism, including against al Qaeda," Donilon said on Fox.
Pakistan, heavily dependent on billions of dollars in U.S. aid, is under intense pressure to explain how bin Laden could have spent so many years undetected just a few hours' drive from its intelligence headquarters in the capital.
Senior Pakistani officials said on Saturday that bin Laden may have lived in Pakistan for more than seven years before he was shot to death by U.S. Navy SEALs.
One of bin Laden's widows told Pakistani investigators that he stayed in a village for nearly 2 1/2 years before moving to the nearby garrison town of Abbottabad.
The wife, Amal Ahmed Abdulfattah, said bin Laden and his family had spent five years in Abbottabad, where one of the most elaborate manhunts in history ended on Monday.
Suspicions have deepened that Pakistan's pervasive Inter-Services Intelligence spy agency, which has a long history of contacts with militant groups, may have had ties with bin Laden -- or that at least some of its agents did. The agency has been described as a state within a state.
Pakistan has dismissed such suggestions and says it has paid the highest price in human life and money supporting the U.S. war on militancy launched after bin Laden's followers staged the September 11, 2001, attacks on the United States.
Donilon said the killing of bin Laden was "a real blow" to the al Qaeda militant network, which he said was still dangerous but in its weakest shape since 2001.
With bin Laden dead, the United States will now turn its attention to his presumed successor, Ayman al-Zawahiri, an Egyptian-born doctor and long time deputy of bin Laden.
"Al-Zawahiri will be ... the number one terrorist we're looking for in the world," Donilon told CNN.
Donilon declined to discuss if evidence uncovered at bin Laden's compound revealed evidence of specific al Qaeda plots against the United States, but said, "It's absolutely critical for us to remain vigilant as we continue to press this organisation."