Missing: four tons of nerve gas, 8.5 tons of anthrax, and assorted nuclear bomb parts

The United States pushed the world closer to armed conflict last night when Colin Powell, the Secretary of State, asserted that Iraq's declaration on its weapons capacities "totally failed" to meet the conditions laid down by the United Nations. The document, he said, was nothing more than "a catalogue of flagrant omissions and recycled information."

Speaking after the two senior UN weapons inspectors had told the Security Council there were serious "holes" in the declaration, General Powell said the shortcomings constituted a "material breach" of Baghdad's obligations – two words that have been treated as a coded trigger for war.

But he indicated the US would not immediately unleash a military campaign. Instead, over the "coming weeks" Washington would seek to intensify UN inspections and secure interviews with Iraqi scientists outside Iraq, while enlisting as broad diplomatic support as possible for the military action that now seems inevitable.

General Powell left only the barest chink of light for Saddam Hussein to comply. The declaration had been a final opportunity to come clean over Iraq's biological, chemical and nuclear capabilities, he said, but "so far" the Iraqi leader had responded "with new lies".

Specifically, he cited major discrepancies between the former production capacity for anthrax and botulinum, two deadly biological agents, admitted by Iraq in the new document, and the findings of the previous UN inspectors after they left Iraq in late 1998. These estimated capacity to be three times larger.

Coupled with Washington's announcement of plans to send 50,000 more troops to the Gulf by mid-January, doubling its military manpower in the region, yesterday's developments in the UN only added to the impression that war is on the way, most likely in early or mid-February.

But while consensus prevailed in the Security Council that Iraq's declaration was broadly unsatisfactory, no other member was ready to back the US in declaring a new material breach. Even Britain, which has stood arm-in-arm with Washington on the issue, declined to utter the words. Ministers in London have said omissions in the text are not in themselves grounds for war. Jack Straw, the Foreign Secretary, said war was not inevitable but Iraq had pulled one "trigger" and "they now have their finger on the other trigger".

The Security Council had met to hear a preliminary assessment of the 12,000-page Iraqi report by Hans Blix, the chief UN weapons inspector, and Mohammed al-Baradei, the chief of the International Atomic Energy Agency. Both men said they would offer a more conclusive analysis of the material in the new year. They are also to give their first formal report on the progress of weapons inspections on 27 January – cited as a possible war decision date for President Bush.

Mr Blix said: "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."

Going further, he said: "There were a lot of open questions at the end of 1998 and these have not been answered. The absence of that evidence means one cannot have confidence that there does not remain weapons of mass destruction."

Iraq reiterated its claim that nothing had been omitted. Amir al-Saadi, a presidential adviser, told a news conference in Baghdad: "It seems they [the US and Britain] are more worried than we are about this assessment. We are not worried. It's the other side that is worried because there is nothing they can pin on us."

Mr Blix and Mr al-Baradei said Iraq had so far co-operated properly and promptly with inspectors, giving them prompt and easy access to sites. But Britain's UN ambassador, Sir Jeremy Greenstock, said it was not enough. "One hundred per cent co-operation [from Iraq] with inspectors is going to be necessary," he warned, "not on process but on the substance of what needs to be cleared up. That will be the test."