Moreover, in the three months since Mr. Hussein's government collapsed, American military forces have found scant evidence of Iraqi chemical or biological weapons.

"That absolutely is incorrect," he said, and he asked for patience as the Pentagon tried to determine if American troops had been exposed to Iraqi chemicals.

The Riegle report urged the government to declassify information related to Iraqi chemical and biological weapons, as well as an epidemiological study involving all Gulf War veterans.

Asked about progress in the hunt for Iraqi chemical, biological and nuclear weapons programs, Mr. Feith said evidence of those programs had been found, but offered no details.

Nor, General Schwarzkopf said, did he recall any confirmed reports during the war that American troops had been exposed to Iraqi chemical or biological weapons.

The major question in the press in recent days has been whether an American attack on Iraq would expose Israelis to the threat of an Iraqi chemical or biological attack.

He also says that "C.I.A. covert paramilitary operators" were placed on teams that searched for evidence of Iraqi chemical and biological weapons.

While current scientific research suggests that Iraqi chemical or biological agents are not responsible for the ailments, it said, the question requires additional research.

Researchers have suggested that low-level exposure to Iraqi chemical or biological weapons may be to blame, but the Defense Department has said it has no evidence of such a link.

The gap has alarmed veterans groups, which say the Defense Department may be hiding evidence of other incidents in which troops were exposed to Iraqi chemical or biological weapons.