The Bush administration has concluded Iraq's weapons declaration fails to explain what happened to chemical and biological agents missing when inspectors were expelled from Iraq four years ago.
Iraq used the 12,000-page document to support its contention - disputed by the United States - that Saddam Hussein's regime has no weapons of mass destruction, officials said.
White House officials have refused comment on the assessment, first reported by the New York Times, but Mr Bush told ABC Newshis gut feeling about Saddam Hussein is that "he is a man who deceives, denies".
Under the terms of UN Resolution 1441, false statements or omissions in the declaration - coupled with a failure to comply with inspections - would be a "material breach" of Iraq's obligations. But weapons inspectors have not publicly accused Iraq of failing to comply.
US officials say the declaration is full of holes, saying it does not explain a number of Iraqi acquisitions that the US suspects are related to Saddam's nuclear programme.
These include the purchase of uranium in Africa and high-tech equipment that could be used in uranium enrichment in Western countries. The report largely rehashes old Iraqi declarations and contains little new information, officials said.
The United States and Russia have turned in their preliminary assessments to chief UN weapons inspector Mr Hans Blix and Mr El Baradei Mohamed of the International Atomic Energy Agency.
Britain, France and China are due to provide their assessments as well and Mr Blix and Mr El Baradei then will remove sensitive sections of the declaration and distribute copies to the 10 other members of the Council.
AP