The outgoing chief U.S. weapons inspector says his inability to find illicit arms in Iraq raises serious questions about American intelligence-gathering.

Last year, David Kay (searchhad confidently predicted weapons would be found. But after nine months of searching, he said Sunday: "I don't think they exist."

"It's an issue of the capabilities of one's intelligence service to collect valid, truthful information," Kay said on National Public Radio.

Asked whether President Bush (searchowed the nation an explanation for the discrepancies between his warnings and Kay's findings, Kay said: "I actually think the intelligence community owes the president, rather than the president owing the American people."

The CIA (search) would not comment on Kay's remarks, though one official, speaking on condition of anonymity, noted that Kay himself was vocal in predicting he would find weapons.

Kay said his predictions were not "coming back to haunt me in the sense that I am embarrassed. They are coming back to haunt me in the sense of `Why could we all be so wrong?"'

The White House stuck by its assertions that illicit weapons will be found in Iraq.

But Massachusetts Sen. John Kerry, a Democratic presidential candidate, said Kay's comments reinforced his belief that the Bush administration had exaggerated the threat Iraq posed.

"It confirms what I have said for a long period of time, that we were misled — misled not only in the intelligence, but misled in the way that the president took us to war," Kerry said on "Fox News Sunday." "I think there's been an enormous amount of exaggeration, stretching, deception."

Kay's comments also drew an I-told-you-so response from Hans Blix, the former chief U.N. inspector whose work was heavily criticized by Kay and came to end when the United States went to war with Iraq.

The United States should have known the intelligence was flawed last year when leads followed up by U.N. inspectors didn't produce any results.

"I was beginning to wonder what was going on. Weren't they wondering too?" He told The Associated Press by telephone. "If you find yourself on a train that's going in the wrong direction, its best to get off at the next stop."

Kay told The New York Times in a later interview for Monday's editions that U.S. intelligence agencies did not realize Iraqi scientists presented Saddam with fanciful plans for weapons programs and then used the money he authorized for other purposes.

"The whole thing shifted from directed programs to a corrupted process," Kay told the Times. "The regime was no longer in control; it was like a death spiral. Saddam was self-directing projects that were not vetted by anyone else. The scientists were able to fake programs."

Kay said Iraq did try to restart its nuclear weapons program in 2000 and 2001, but that evidence suggests it would have taken years to rebuild after being largely abandoned in the 1990s.

He said it is now clear that the CIA's basic problem was that the agency lacked its own spies in Iraq who could provide credible information, but that he does not believe analysts were pressed by the administration to make their reports conform to a White House agenda.

Sen. Pat Roberts, R-Kan., chairman of the Senate Intelligence Committee, said he was surprised Kay "did not find some semblance of" banned chemical, biological or nuclear weapons in Iraq. Roberts said a report on Iraq intelligence, to be delivered to his panel Wednesday, should help clarify the CIA's prewar performance.

"It appears now that that intelligence — there's a lot of questions about it," Roberts said Sunday in a televised interview.

In October 2002, Bush said Iraq had "a massive stockpile of biological weapons that has never been accounted for and is capable of killing millions." In his television address two days before launching the invasion, Bush said U.S. troops would enter Iraq "to eliminate weapons of mass destruction," or WMD.

Kay returned permanently from Iraq last month, having found no such weapons, nor missiles with longer range than Saddam was allowed under international restrictions.

But on Sunday, Kay reiterated his conclusion that Saddam had "a large number of WMD program-related activities." And, he said, Iraq's leaders had intended to continue those activities but had not decided whether to begin producing such weapons at the time of the January invasion.

Kay also said chaos in postwar Iraq made it impossible to know with certainty whether Iraq had had banned weapons.

And, he said, there is evidence that Iraq was moving a steady stream of goods shipments to Syria, but it is difficult to determine whether the cargoes included weapons, in part because Syria has refused to cooperate in this part of the weapons investigation.

Kay said he resigned Friday because the Pentagon began peeling away his staff of weapons searchers as the military struggled to put down the Iraqi insurgency last fall.

Kay hopes to draw on his experiences to write a book on weapons intelligence.