Washington: The United States denied having any information or concrete evidence so far which indicates that the Pakistani establishment had knowledge or information about the hideout of slain al-Qaeda chief Osama bin Laden in a garrison town near Islamabad.

"We have no definitive evidence at this point that they knew if Osama bin Laden was at this compound," said Under Secretary of Defense for Policy Michele Flournoy, the first Pentagon official to comment on-the-record about the raid on Friday.

Questions about whether Pakistan knew of bin Laden's whereabouts, and may even have helped hide him, arose immediately after Monday's raid in which the al-Qaeda chief was killed in garrison town near Islamabad.

Flournoy, one of the three co-authors of the Af-Pak policy of the Obama administration, however, said that the US has sought more details from Pakistan on this issue as questions are being raised as to how bin Laden can stay so close to a military establishment without any support system.

The United States is talking with the Pakistanis to try to understand "what they knew and what they didn't know" with regard to bin Laden hiding in plain sight at a one-acre compound in Abbottabad, she said in her remarks to the Aspen Institute.

"There's great opportunity for cooperation (from Pakistan) in making sense of what we learn from the materials gathered in the operation," Flournoy said, adding that "from understanding the network as it remains and how to put further pressure on the network to hasten its demise, and more broadly to cooperate in a way that ultimately helps stabilize not only Pakistan but Afghanistan."

Flournoy described the contacts with Pakistan as "very candid," and stressed the need for concrete moves on the Pakistanis' part to prove their commitment.