President Bush and Vice-President Dick Cheney met in private Thursday with all 10 members of the commission investigating the September 11, 2001 terrorist attacks on the United States. The historic session took place behind closed doors in the president's office.

The commission wants to know what the White House knew before the attacks and how it responded to the terrorist threat.

The president says he answered every question the commissioners asked.

"It was a very cordial conversation," he said. "I was impressed by the questions."

The session, which took place in the Oval Office, lasted more than three hours. Mr. Bush describes the meeting as important and wide-ranging, and indicates the tone was bipartisan.

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

Mr. Bush says he will not discuss the substance of the questions, although he says there was a lot of interest in how to better protect America. He says the commission members will take all they have learned and incorporate it into their final report.

"They are very interested in the recommendations they are going to lay out and I am interested in those as well," he said.

The private meeting took place under ground rules set by the White House and accepted by the commission. The president and vice-president appeared together, neither answered questions under oath, and there was no recording or transcript of the session, only handwritten notes taken by commission and White House staff.

Appearing in the White House rose garden about half an hour after the commissioners left, President Bush said he thought the format worked well. He said every question posed to Mr. Cheney also got an answer.

"And I think it was important for them to see our body language as well, how we work together," said President Bush. "You know, the commissioners will speak for themselves over time. They will let you know whether they thought it was a fruitful series of discussions. I think they did. I think they found it to be useful."

In a statement issued by the commission after the meeting, the members of the panel said they found the president and vice-president to be forthcoming and candid. The five Republican and five Democratic Party commissioners said the information provided will be of great assistance as they complete their final report. That report is due in late July, as the presidential election campaign is moving into high gear.