Duelfer spoke as his Iraq Survey Group issued a report saying Iraq did not have weapons of mass destruction at the time of the US-led invasion in March

The inspector told the Senate Armed Services Committee that some small finds had been made of chemical and nerve agents dating from before 1991. Some tips were also to be followed up.

"Despite these reports and finds, I still do not expect that militarily significant WMD stocks are cached in Iraq," Duelfer said.

While Saddam Hussein hoped to develop a long-range missile system, his weapons development program was in such disrepair that little work was ever done on warheads, Duelfer said.

After weapons inspections began 1991, Saddam sidelined chemical and biological weapons programs with an eye toward future development, Duelfer said.

"As in the other WMD areas, Saddam sought to sustain the requisite knowledge base to restart the program eventually and ... to sustain the inherent capability to produce such weapons as circumstances permitted in the future," he told the panel.

He said that if there was any risk posed by Saddam it was years in the future, far from the immediate risk US officials insisted the Iraqi leader posed.

When challenged by Democratic Senator Ted Kennedy about the group's "wild goose chase" for WMD's despite months of looking and millions of dollars spent, Duelfer defended the effort.

"My task was not to find weapons of mass destruction, my task was to find the truth," he told the committee.

Duelfer could not explain why Saddam did not try harder to cooperate with UN weapons inspectors in a bid to avoid invasion by the United States and its allies.

"It's a question which many of us have puzzled over," he said. "It really requires you to get into Saddam's mind.

"The answer is, it's difficult to know for certain," continued Duelfer, who said Saddam apparently failed to understand that business as usual no longer applied after the September 11, 2001 terror attacks on the United States.

"He wanted to get sanctions lifted. He kept trying to bargain and barter and had not realized the nature of the ground shift in the international community," Duelfer told the senators.

"That was Saddam's intelligence failure," he said. "He did not understand very quickly the dramatic change of the international landscape."

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