After days of saying that he would only give one hour to the commission studying intelligence failures before the Sept. 11, 2001, terror attacks, White House officials said Tuesday that nobody will be watching the clock when President Bush meets with the panel to answer questions.

"Obviously you have to set parameters when you're talking about a sitting president of the United States, and we believe we set aside a reasonable period of time. But the president intends to answer all their questions," White House Press Secretary Scott McClellan told reporters.

The decision to expand the commission's access to the president came one day after presumptive Democratic presidential nominee John Kerry (search) accused Bush of finding more time for the Texas rodeo than for a commission investigating the nation's intelligence failures. Bush stopped in on the rodeo while in Houston on Monday.

After hearing of Bush's decision, Kerry still blasted the president.

"It's good to see that the president has finally found time in his schedule to spend more than an hour with the 9/11 commission to investigate the greatest intelligence failure in our nation's history. I think all Americans hope that his cooperation with the commission will lead to real answers instead of more stonewalling," he said. 

The National Commission on Terrorist Attacks on the United States (search) was created by Congress and approved by Bush to look at government missteps before the 2001 terror attacks, including miscommunications about Al Qaeda (search) operatives and weak border entry rules that allowed some of the Sept. 11 hijackers to enter the United States repeatedly on bad visas.

The panel has not blamed anyone beyond midlevel officials in federal agencies, and the administration would like to make sure that it doesn't start now.

McClellan said the White House has provided "unprecedented cooperation" to the commission, but a separation of powers issue is involved in a sitting president answering questions from Congress.

"Historically, White House staffers do not testify before legislative bodies," he said.

National Security Adviser Condoleezza Rice (search) has already sat down to more than four hours of questioning, at a meeting in which only half the commission members showed up. She has refused to give out public testimony, which could be sensitive to national security.

McClellan added that none of the 10 commission members has been to all the commission hearings. Chairman Thomas H. Kean (search) acknowledges that the group has received all that it has asked for, said McClellan, though some Democrats on the commission have complained that they have not. McClellan read off a list of materials the White House has provided.

"More than 800 audio cassette tapes of interviews and other materials, more than 100 briefings, including at the head-of-agency level and more than 560 interviews. We bent over backwards," he said.

The controversy comes as the Bush campaign has been criticized for using images of the aftermath of the World Trade Center (search) attack in its ads. A firefighters union that endorsed Kerry led the charge.

A few weeks ago, Congress agreed to extend the commission's deadline by a couple months, to the end of July. Republican leaders on Capitol Hill hadn't wanted to release the findings then, saying it was so close to the election they would be used for political purposes. But GOP leaders gave in.

The flexibility over the time limit for the president's interview suggests the administration is doing what it can to avoid another conflict. Aides say despite the flexibility over the time limit, the president has not changed his mind that he will meet only with Kean and Vice Chairman and former Indiana Democratic Rep. Lee Hamilton (search) for the interview. The two had said that it is unnecessary for Bush to testify publicly. Officials said they can share the president's answers with the eight other members.

The White House and the commission are working on a date for the meeting with Bush. Some commission members will also meet with Vice President Dick Cheney.

Fox News' Wendell Goler contributed to this report.