The United States is turning up the pressure on Iraq before the Sunday deadline by which Baghdad must reveal all its weapons programmes to the United Nations to comply with a resolution.

The BBC's Justin Webb in Washington says US officials are not revealing what information they have, in order to force Iraq to guess what it might be.

Saddam urged his people to give the inspectors a chance to clear Iraq's name

Then if Iraq - which maintains it has no banned weapons - tells the UN something which can be shown to be false, the US could direct weapons inspectors towards a target and possibly hasten action against Saddam's regime, our correspondent says.

The US has called for inspections ordered under the UN resolution to be stepped up.

Defence Secretary Donald Rumsfeld said it was vital that the UN ensured that the terms of the resolution passed unanimously by the Security Council last month were being met.

He said Iraq had weapons of mass destruction and could either declare them or try to continue to cover them up.

Iraqi 'lies'

White House spokesman Ari Fleischer refused to give details on what evidence the US had, but said intelligence would be passed on to the inspectors in Iraq.

"The president of the United States and the secretary of defence would not assert as plainly and bluntly as they have that Iraq has weapons of mass destruction if it was not true, and if they did not have a solid basis for saying it," he said.

On Wednesday, Iraqi Deputy Prime Minister Tariq Aziz told a US television network that Iraq had no chemical, biological or nuclear weaponry, though some innocent equipment could be deemed as "dual use" with a possible military capability.

A false declaration would make clear to the world that Saddam's strategy is deceit - we will not allow him to get away with it

UK Foreign Secretary Jack Straw

Mr Fleischer responded: "That statement is just as false as statements that Iraq made in the late 90s when they said they had no weapons of mass destruction, when it was found they indeed did. There is no basis to that."

President Bush himself refused to be drawn directly on what could trigger a war, saying that was a question for Saddam Hussein.

But in London, British Foreign Secretary Jack Straw reminded Iraq that it risked an attack if it provided an inaccurate account of its weapons programmes.

"While this weekend will not be the moment to declare Iraq either in breach or in compliance, a false declaration would make clear to the world that Saddam's strategy is deceit," Mr Straw said.

"We will not allow him to get away with it."

Dossier promise

A senior Iraqi official in Baghdad has said Iraq will present its dossier on Saturday - before the deadline set in the UN resolution which was written jointly by Britain and the US.

The weapons inspectors who returned to Iraq after a four-year absence will not make any searches on Thursday or Friday in respect for the Eid al-Fitr festival at the end of the holy month of Ramadan.

Iraqi President Saddam Hussein urged his people to give the inspectors a chance and be patient in the face of what he called "unjust, arrogant, debased American tyranny".

In a televised speech, he said Iraq had accepted the inspectors "to keep our people out of harm's way" and in the hope that American allegations could be disproved.

His Vice-President, Taha Yassin Ramadan, has accused inspectors of being spies, but that has been rejected by the weapons teams.