Mr Powell said that omissions in the document constituted a "material breach" of the resolution, echoing an earlier statement from the US ambassador to the UN, John Negroponte.
"
It should be obvious that the pattern of systematic holes and
gaps in Iraq's declaration is not the result of accidents or editing
oversights or technical mistakes
"
Secretary of State Colin Powell
Mr Powell said that the burden was on Iraq to prove that it did not possess weapons of mass destruction, warning that Baghdad was "well on its way to losing this last chance".
Resolution 1441, which led to the return of weapons inspectors to Iraq, threatens Baghdad with "serious consequences" if it fails to comply with UN disarmament demands.
Washington had said that if Iraq was found to be in material breach of this resolution it would authorise an immediate attack - although for now the US administration has said it will continue to support the work of the UN inspectors.
'Missed opportunity'
Earlier, the UN's chief weapons inspector Hans Blix and the head of the International Atomic Energy Agency, Mohamed El Baradei, criticised the document too.
"We are consistent in the view that there has been relatively little given in the declaration by way of evidence concerning the programs of weapons of mass destruction," Mr Blix said after the Security Council briefing.
Mr Blix said evidence that weapons that were known to exist in the 1990s had really been destroyed was missing from the document.
IRAQI MATERIAL UNACCOUNTED FOR
"An opportunity was missed in the declaration to give a lot of evidence. They can still provide it orally but it would have been better if it was in the declaration," Mr Blix added.
Mr Blix said that further analysis would be carried out and inspections would continue in Iraq.
He added that he would return with the head of the IAEA, Mohamed El Baradei, to the Security Council in January.
Iraqi rejection
Iraq's deputy UN Ambassador Mohammed Salmane dismissed the US charges as "baseless," saying:
"I would like to confirm that the Iraqi declaration is complete and comprehensive." He added that this would be borne out by the inspection being carried out in Iraq.
Mr Powell called Iraq's 12,000 page declaration "a catalogue of recycled information and flagrant omissions".
He added that the declaration was "an attempt to sow confusion and buy time" and that as such it failed to move its relations with the US in a peaceful direction.
Intelligence sharing
Mr Powell said that there were now three steps on how the UN should proceed to address this issue:
He also said that the US would continue to consult with its allies and the Security Council on how to "compel compliance".
Significantly he called on the international community to offer all possible assistance to the inspectors, which the BBC's diplomatic correspondent, Brian Hanrahan, said pointed to the US sharing its intelligence on Iraq with the inspection team.