The chief United Nations weapons inspector, Hans Blix, has distributed a lengthy document to Security Council members containing a wide range of questions he says Iraq has failed to answer about its weapons programmes.
A vote on Britain's draft resolution could come as early as Tuesday
The document was handed out after his latest report on Iraqi co-operation in disarming, in which he praised Iraq's decision to destroy its al-Samoud II missiles.
The UK has presented a revised draft resolution to the Security Council, giving Iraq an ultimatum to disarm by 17 March or face military action.
The US is pressing for a vote to take place on Tuesday or soon after.
Mr Blix said Iraq's co-operation had improved recently, but the document he has circulated outlines the many areas where questions remain.
The dossier details the weapons of mass destruction Iraq may still possess:
- Up to 10,000 litres of anthrax
- Scud missile warheads fitted with deadly biological and chemical agents
- Pilot-less aircraft, or "drones", that intelligence reports say far exceed the 150 kilometre (93 mile) limit allowed by the UN
The UK Foreign Minister Jack Straw said the document was "a shocking indictment of the record of Saddam Hussein's deception and deceit, but above all, of the danger which he poses to the region and to the world."
Analysts say the UK and US will use Mr Blix's dossier to support their argument that Iraq has failed to disarm fully and must now be disarmed by force. Meanwhile, countries opposed to war will see the dossier merely as a list of disarmament obligations for Iraq over the coming months.
Countdown to war
The BBC's Justin Webb in Washington says if a new resolution is passed, the US would respect the March deadline - but if it is rejected it is likely that President George W Bush would address the nation and send his troops into battle within hours.
Mr Straw has said he believes a second resolution on Iraq will be adopted in the end.
"I believe that by the process of argument we can get to the point where we can have a second resolution," he told the BBC.
But the draft resolution has been criticised by France, one of the five countries which holds the power of veto on the Security Council.
The French Foreign Minister, Dominique de Villepin, said imposing a deadline of only a few days was a pretext for war.
Germany, along with veto-wielders China and Russia, also expressed concern.
In other developments:
- Iraq says it has begun destroying another six al-Samoud II missiles. It would raise to 40 the number of missiles destroyed since the operation began a week ago.
- Iraqi newspaper Babel - which is run by President Saddam Hussein's son Uday - says the reports by the weapons inspectors were "fair".
- Mohammed ElBaradei, head of the International Atomic Energy Agency, tells the BBC that inspections are making progress and should be given more time.
The Iraqi ambassador to the UN said it seemed a war of aggression was going to go ahead, no matter what the Security Council decided.
But Mr ElBaradei said: "The ball is very much in Iraq's court."
"I hope Iraq will understand they need to have a dramatic change (in) their attitude," he told BBC Radio Four's Today programme.
In his report to the Security Council, Mr ElBaradei said there was no evidence that Iraq had restarted the nuclear weapons programme it was forced to abandon after the 1991 Gulf War.
Mr Blix said inspectors had been able to conduct operations throughout Iraq with relative ease and described the ongoing destruction of al-Samoud II missiles as a "substantial measure of disarmament".
But he said such co-operation could not be described as "immediate compliance" - as required by Resolution 1441, passed late last year by the Security Council.