Washington: President George W Bush and Vice President Dick Cheney answered questions today from September 11 Commissioners trying to learn how followers of Osama bin Laden pulled off the worst terrorist attack in American history.

"I answered every question,'' Bush told reporters after the session lasting over three hours.

Speaking with reporters in the White House Rose Garden, Bush declined to say what topics the Commission focused on during a meeting that lasted over three hours. But he did say the session was cordial. "I'm glad I did it. I'm glad I took the time...I enjoyed it.''

The 10 Commissioners gathered around Bush and Cheney, who were seated on chairs near the fireplace in the Oval Office for an unprecedented closed-door meeting that was off-limits to all but White House counsel Alberto Gonzales and two members of his staff.

Asked why Bush felt it necessary to appear jointly with Cheney, the President vigorously defended that arrangement.

"If we had something to hide, we wouldn't have met with them in the first place," Bush said. Critics have suggested the two men met together to make certain there were no discrepancies in their statements.

While he declined to say what the questions focused on, Bush told reporters, "I was never advised by my counsel not to answer anything. I answered every question they asked."

"There was a lot of interest about how to better protect America," he said. "They're very interested in the recommendations that they're going to lay out and I'm interested in that as well."

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

In a statement issued by the panel after the meeting, Commissioners said they found the President and Vice President "forthcoming and candid".

"The information they provided will be of great assistance to the Commission as it completes its final report. We thank the President and the Vice President for their continued co-operation with the Commission," the statement said.