President Bush said Monday that he declassified sensitive prewar intelligence on Iraq back in 2003 to counter critics who claimed the administration had exaggerated the nuclear threat posed by Saddam Hussein.

President Bush participates in a question and answer session after delivering remarks on the global war on terror at the John Hopkins University's Paul H. Nitze School of Advanced International Studies in Washington Monday, April 10, 2006. [AP]

"I wanted people to see the truth and thought it made sense for people to see the truth," Bush said during an appearance at Johns Hopkins University's Paul H. Nitze School of Advanced International Studies.

"You're not supposed to talk about classified information, and so I declassified the document," he said in a question-and-answer session after delivering a speech on Iraq. "I thought it was important for people to get a better sense for why I was saying what I was saying in my speeches. And I felt I could do so without jeopardizing ongoing intelligence matters, and so I did."

It was Bush's first comment since more detail about the release of a prewar intelligence document surfaced last week in a court filing by U.S. prosecutor Patrick Fitzgerald.

In the filing, Fitzgerald wrote that Vice President Dick Cheney's former chief of staff, I. Lewis Libby, told a grand jury that Bush authorized him, through Cheney, to leak information from a classified document that detailed intelligence agencies' conclusions about weapons of mass destruction in Iraq.

A lawyer knowledgeable about the case said Saturday that Bush declassified sensitive intelligence in 2003 and authorized it to be publicly disclosed to rebut Iraq war critics. But the lawyer said Bush did not specifically direct Libby to disseminate information about prewar intelligence to reporters.

Sen. Chuck Schumer, D-N.Y., sent a letter to Bush on Monday asking him for details about how the document was declassified. "There are many questions that the president must answer so that the American people can understand that this declassification was done for national security purposes, not for immediate political gain."

Bush's decision in July 2003 to disclose sensitive prewar intelligence assessments came amid a growing public realization that Iraq had no weapons of mass destruction. The failure to find such weapons undermined a chief rationale Bush and Cheney used for the U.S.-led invasion of Iraq.

On Sunday, Sen. Arlen Specter (news, bio, voting record), R-Pa., said Bush and Cheney should speak publicly about the CIA leak case so people can make their own judgments about what happened. But Bush said he can't talk about an ongoing legal proceeding.

"You're just going to have to let Mr. Fitzgerald complete his case," Bush said. "And I hope you understand that. It's a serious legal matter that we've got to be careful in making public statements about it."

Libby faces charges of perjury, obstruction and lying to the FBI regarding the disclosure that Valerie Plame, the wife of war critic Joseph Wilson, worked for the CIA. Libby is accused of making false statements about how he learned of her CIA employment and what he told reporters about her.

Plame's CIA employment was disclosed by conservative columnist Robert Novak eight days after her husband, Wilson, accused the Bush administration of manipulating prewar intelligence to exaggerate the Iraqi threat from weapons of mass destruction.