Washington ? Hoping to shape history’s judgment, President Bush told the Sept. 11 commission Thursday his administration tried to protect America from terrorists as warnings grew before the devastating 2001 attack. Members pressed him on his response to a controversial memo that raised the threat of plane hijackings and attacks with explosives.

“I answered every question they asked,” Bush said after he and Vice President Dick Cheney met with the 10-member commission for three hours in the Oval Office. Presidential scholars called the session unprecedented.

Some of Bush’s answers were “surprising” and “new,” said former Sen. Bob Kerrey, a Democratic member, but he declined to give details. On Bush’s demand, the questioning was done behind closed doors without a transcriber to make an official record, and the president refused to discuss the substance of the discussions.

Bush and Cheney faced questions about the lack of a U.S. military response after the 2000 bombing of the USS Cole that killed 17 American sailors, the administration’s response to 9-11 and the memo Bush received a month before the attacks warning that Osama bin Laden was preparing to strike, commission members said.

It was Bush who responded to most of the questions, officials said. Cheney spoke only when Bush turned to him about details he didn’t know, according to one participant.

Charged with investigating the 9-11 hijackings and recommending steps to prevent future attacks, the commission has documented a string of urgent warnings communicated to the highest levels of government before 9-11.

“I was impressed by the questions,” the president said. “I think it helped them understand how I think and how I run the White House and how we deal with threats.”