UN Secretary-General Kofi Annan has warned world leaders to think carefully about the consequences of military action against Iraq.

Mr Annan, who has argued that diplomacy should still be allowed to run its course, said it was time for the UN Security Council to make its views heard.

What sort of Iraq do we wake up to after the bombing?

Kofi Annan UN Secretary General

His comments come ahead of the annual UN general debate which begins in New York later this week.

Among the first speakers is US President George W Bush, who is seeking support for his campaign to topple Iraqi leader Saddam Hussein.

Mr Bush was in contact with Mr Annan early on Monday.

When Mr Annan spoke to reporters later he reflected on many of the uncertainties other world leaders have expressed to him.

UN weapons inspectors left Iraq in 1998

"I know many people are worried about unexpected consequences. And it's difficult to predict.

"The question is the morning after. What sort of Iraq do we wake up to after the bombing?," Mr Annan said.

"And what happens in the region? What impact would it have?"

Mr Bush's spokesman has claimed the US is beginning to win the argument for tougher action against Iraq.

In a new report published on Monday, an influential London think-tank said Baghdad could produce a nuclear weapon within months.

However, the International Institute for Strategic Studies said Saddam Hussein would first need to obtain supplies of radioactive material.

It also concluded that Iraq has probably been successful in hiding large stockpiles of chemical and biological weapons from UN inspectors, as well as a small number of long-range missiles.

Iraqi media tour

Iraqi officials escorted western reporters to two sites on Monday in an effort to show that Saddam Hussein was not rebuilding sites linked to past nuclear projects or training terrorists.

Iraq says it has no desire to build weapons of mass destruction

Former UN weapons inspector Scott Ritter, who accompanied reporters to Salman Pak, 40 kilometres (25 miles) east of Baghdad, said the base was being used for anti-hijack training - not for terrorism training.

Reporters also toured the Al-Tammuz reactor site at Al-Toweitheh, 40 km south of Baghdad.

The UN says there has been unexplained activity at the site, but the Iraqis claim the facility is used for pharmaceutical research.

US diplomatic push

Mr Bush is expected to set out his case for dealing with the threat posed by Iraq on Thursday.

The BBC's Greg Barrow at the UN in New York says there is much talk among diplomats there about the possibility of adopting a new resolution demanding that Iraq re-admits UN weapons inspectors.

Bush has made no secret of his desire for "regime change" in Iraq

Last week, President Bush was reported to be considering asking for a resolution that would set a deadline for weapons inspections to resume.

On Monday, White House spokesman Ari Fleischer declined to say if the US president would back any new resolutions on Iraq.

However he did say it appeared that a movement was "budding" to put some force into previous UN resolutions.

"Don't take it as military force, necessarily," he said.

French President Jacques Chirac earlier proposed a two-stage plan that could lead to UN authorisation of military force against Iraq.

Such a process would begin with a Security Council resolution giving Baghdad three weeks to readmit arms inspectors.

If Iraq failed to comply, another resolution could back the use of force, Mr Chirac said, appearing to soften France's previous opposition to US plans.

Germany has dismissed military intervention in Iraq as an "adventure" in which Berlin will not take part.

Among European nations, only Britain has voiced support for the US.

The Vatican is the latest state to call for UN authorisation for any strike.

Any action "must be part of a decision taken within the framework of the United Nations," Vatican Foreign Minister Archbishop Jean-Louis Tauran, said in comments to be published on Tuesday, Reuters news agency reported.

US warplanes again attacked an air defence target in the air exclusion zone over southern Iraq on Monday, in response to continuing attempts to shoot down patrolling jets, the US military said.