UK Foreign Secretary Jack Straw has warned the international community must not "stand by and do nothing" while Saddam Hussein "persistently mocks" the UN.

Iraq had clearly breached the United Nations' Security Council resolutions and a deadline should be imposed for the readmission of weapons inspectors, the minister said.

Saddam Hussein is accused of "mocking" UN

Mr Straw stressed every member state of the organisation had a responsibility to act or the authority of the UN itself was at stake, in a speech to the UN general assembly on Saturday.

His speech came after US President George Bush said millions of lives and world peace could be at stake if action was not taken against Iraq.

The case for a strong stand by the UN and Congress was "quite straightforward" the president said.

Mr Straw said the UN had to be clear to Baghdad and to itself of the "consequences which will flow from a failure by Iraq to meet its obligations".

But he sought to calm fears about the US and Britain acting alone by making clear that any action against Iraq must secure the will of the UN.

'A dangerous place'

"We cannot let the United Nations' unique authority, leading the international community, be undermined by those who have no respect for it.

"It is the responsibility of all of us here in this assembly to ensure that the legitimacy, the authority and the capacity of the UN to preserve peace and to build prosperity is strengthened, not undermined."

Bush said world peace was at stake

If the UN failed to deal with the challenge of Iraq, it would be "seriously weakened", making the world a much more dangerous place, the foreign secretary said.

Weapons of mass destruction posed the greatest threat to global security, he said.

Iraq was "infamous" as being the only country to defy the Non-Proliferation Treaty, the Chemical Weapons Convention and the Biological and Toxin Weapons Convention.

Saddam's regime had "defied and frustrated every attempt to enforce the international rule of law" for two decades, Mr Straw said.

On Friday, Mr Straw had said a strict time limit should be set on Iraq allowing weapons inspectors in and US President George W. Bush had warned the deadline would be "days and weeks, not months and years" away.

But Iraq's deputy Prime Minister, Tariq Aziz, rejected demands for an unconditional return of inspectors.

Earlier on Saturday, the UK's Deputy Prime Minister John Prescott added his voice to a campaign to rally support for the government's strategy on Iraq.

He said he personally endorsed Prime Minister Tony Blair's stance towards Iraq.

Mr Blair has apparently swayed Washington to seek a UN mandate before any action is taken.