WASHINGTON — U.S. intelligence analysts never concluded that Saddam Hussein's regime posed an imminent threat to the United States before President Bush launched the war against Iraq, CIA director George Tenet said Thursday in a vigorous defense of the intelligence community.

Analysts had far from a "perfect picture" of pre-war Iraq, Tenet conceded in a speech at Georgetown University. He said gaps in their ability to fully assess the threat prompted fears that Baghdad was operating a secret weapons program that "might constantly surprise us and threaten our interests."

In the months before launching the invasion of Iraq, President Bush and other administration officials cited intelligence about Iraq's possession of banned weapons to argue the urgent need to disarm Saddam.

Tenet insisted that neither Bush nor anyone else pressured CIA analysts to come up with threat assessments that strengthened the case for war.

"No one told us what to say or how to say it," Tenet said.

The Bush administration has come under mounting scrutiny in recent weeks amid public statements by former U.S. weapons inspections chief David Kay that the intelligence community erred in determining that Saddam possessed chemical and biological arms.

In a speech Thursday, Bush addressed the issue, conceding: "We have not yet found the stockpiles of weapons that we thought were there."

Instead, said Bush, inspections have turned up laboratories and dual-use facilities that would be capable of building chemical and biological arms, thus revealing Saddam's desire for weapons of mass destruction.

"Knowing what I knew then, and knowing what I know today, America did the right thing in Iraq," Bush said in a speech in Charleston, S.C. "We had a choice: either take the word of a madman, or take action to defend the American people."

Nearly 10 months after the fall of Baghdad, U.S.-led inspectors have not found evidence of banned weapons stockpiles assumed still to be part of Saddam's arsenal since the 1991 Gulf War. The United Nations and other international bodies have documented incidents when Iraq used chemical weapons in the Iran-Iraq war and against its Kurdish minority during the 1980s.

Tenet said the U.S. inspection team in Iraq is "nowhere near the end of our work."

"We need more time and we need more data," he said, before drawing conclusions about Iraq's possible chemical and biological arsenals.

Tenet conceded that Iraq appears to have made less progress than U.S. analysts assumed in seeking to acquire nuclear weapons. "We may have overestimated the progress" in that area, Tenet said.