President Bush (search) wants his staff to cooperate with investigators trying to find out whether a Bush administration official leaked a CIA operative's name, but the White House won't say whether he'll ask staffers to release reporters from confidentiality agreements.

Signing such confidentiality waiver forms could persuade reporters to disclose their confidential sources. That might help investigators find out if a Bush administration official leaked the name of Valerie Plame (search), an undercover CIA officer, to syndicated columnist Robert Novak in July.

Plame is married to former Ambassador Joseph C. Wilson (search), who has said he thinks his wife's identity was disclosed to discredit his assertions that the Bush administration exaggerated Iraq's nuclear capabilities to build a case for war.

"The president has directed the White House to cooperate fully with the career officials who are leading this investigation, and that's exactly what he expects the White House to continue doing," White House press secretary Scott McClellan told reporters Monday aboard Air Force One en route to St. Louis for an education event and campaign fund-raiser.

"It's important that we do everything we can to preserve the integrity of the investigation and not compromise it," McClellan said.

He would not say whether the president would direct his staff to sign such agreements or whether any forms had been requested.

The FBI has interviewed more than three dozen Bush administration officials. The leaker could be charged with a felony.

"The president has always said that leaking classified information is a serious matter, and certainly no one wants to get to the bottom of this more than he does, so that we can find out the truth," McClellan said. "The president has said from early on that if anybody has information, they should come forward and share it with those who are leading this investigation.

McClellan referred all questions to the Justice Department.

Attorney General John Ashcroft removed himself last week from the inquiry to avoid the appearance of a conflict of interest. Democrats had been calling for Ashcroft to step down. U.S. Attorney Patrick J. Fitzgerald of Chicago, a career prosecutor, will lead the probe.