President Obama's top counterterrorism adviser called it "inconceivable" that Pakistan was not providing a "support system" for Osama bin Laden, who was killed Sunday in a raid in a mansion north of the capital city of Islamabad.
"We are pursuing all leads on this issue," Deputy National Security Adviser John Brennan said during a White House briefing. "I think people are raising a number of questions, and understandably so."
He said the administration is in contact with Pakistan's government and intelligence establishment about the situation.
Brennan called Obama's decision to launch an operation against bin Laden one of the "gutsiest calls" in recent history — he said the operation was based on "actionable" intelligence, but "there was nothing to confirm" the al Qaeda leader was in the compound in Abbottabad.
The president made "one of the gutsiest calls of any president in recent memory," Brennan said, calling it a "defining moment" in the war on terror.
Despite a sense of relief inside the Obama administration and around the country, Brennan said many questions still remain about the incident, specifically about bin Laden's connections in Pakistan.
Brennan confirmed that the Pakistanis were kept out of the loop on the attack until U.S. forces were out of their airspace. Pakistani forces did not engage with Americans involved in the mission, he said.
He was also careful to praise the Pakistanis for being "as much if not more on the front lines against terrorism.
"It can be a complicated matter," he said. "We don't always agree."
Brennan described "tense" moments in the White House Situation Room, where Obama and his national security team were monitoring the strike. A helicopter malfunctioned during the operation and had to be destroyed after it landed within the compound.
"The minutes passed like days, and the president was very concerned about the security of our personnel," Brennan said.
Brennan also said that the U.S. is continuing to deliberate whether or not to release photos or other details about bin Laden's body, which was buried at sea less than 24 hours after he was killed.
"We are going to do everything we can" to ensure that nobody has a "basis" for denying he was killed, Brennan said. "This is something to be determined."
Brennan also revealed that the woman killed in the operation was a wife of bin Laden, who was used as human shield to protect him. But Reuters later reported, citing an anonymous White House official, that she was injured, not killed, in the attack.
When the mission was accomplished "It was a tremendous sigh of relief," Brennan said. "The president was relieved once we had our people and those remains off target."
-- This post was updated at 9:23 p.m.