In comments afterward in the White House Rose Garden, Bush declared the extraordinary, three-hour-and-10-minute session a success that he hoped would lead to recommendations about how to guard against future attacks because "we are still vulnerable to attack."

He dismissed criticism from Democrats that he wanted to appear together with Cheney so they would not contradict each other.

"Look, if we had something to hide we wouldn't have met with them in the first place. We answered all their questions. As I say, I came away good about the session because I wanted them to know how I set strategy, how we run the White House, how we deal with threats," Bush said.

The president had only agreed to meet the commission under pressure from victims' families and the panel, and only on condition he have Cheney at his side and they meet in private, with no recording of the session. They were not under oath.

Against a backdrop of a presidential campaign year and amid fears that al Qaeda operatives are planning a new attack in the United States, Bush and Cheney gathered with the five Republicans and five Democrats on the commission in the very heart of presidential power, the Oval Office.

Bush and Cheney were seated on chairs by the fireplace, and commission members were scattered on couches and chairs. Their talks went back to the transition period between the departing Clinton White House and the incoming Bush team.

A commission source said the meeting turned up some new information for the panel. "We learned a lot," the source said without elaborating. "There was quite a bit we hadn't known."

Citing several sources, NBC News reported Bush revealed new details about the chaos of Sept. 11. In one example of the confusion of that day, officials at the White House were worried about a flight from Spain and wanted permission to shoot it down if necessary, NBC said. Bush told the commission he issued that order after arriving at Strategic Command headquarters in Omaha, Neb. and learned later the plane had turned back to Madrid, according to the report.

NBC also reported that Bush was critical of his former counterterr-orism chief, Richard Clarke. Clarke has said Bush did not heed his warnings that al Qaeda was an urgent threat.

The White House, reluctant to provide details, acknowledged one area of questioning was related to Bush's response to an Aug. 6, 2001, presidential intelligence memo entitled "Bin Ladin Determined to Strike In US" that Bush released under pressure from the commission on April 10.