The United Nations chief weapons inspectors have set tough new conditions for holding a fresh round of talks with Iraqi officials.

UN officials said Hans Blix and Mohamed ElBaradei would return to Baghdad on 8 February, but are insisting on greater co-operation from Iraq on issues including surveillance flights and interviews with scientists.

Inspectors checked 11 sites for evidence on Saturday

US President George W Bush has warned he will not tolerate any attempt by Baghdad to delay possible military action by "stringing along" inspectors.

UK Defence Secretary Geoff Hoon has said Iraqi President Saddam Hussein "can be absolutely confident" the UK is willing to use nuclear weapons "in the right conditions", and would use them "in extreme self-defence".

Mr Hoon said there was no fixed timetable for war, and that a further discussion would be necessary in the UN Security Council if a material breach of resolution 1441 was declared.

He said that, if and when that happened, Britain would make "a very determined effort" to secure a second UN resolution giving backing for military action against the Iraqi leader.

Areas of concern

A UN spokeswoman said Mr Blix and Mr ElBaradei wanted "to do everything they could to achieve disarmament through inspections".

Before accepting Iraq's invitation, both men said they would seek substantial progress in areas of concern.

Specifically, they want the Iraqis to:

• Address data said to be missing from Iraq's weapons declaration such as the whereabouts of suspected stocks of VX nerve gas and anthrax
• Support private interviews of scientists
• Accept surveillance flights from U-2 spy planes

Inspectors inside Iraq failed to interview a scientist on his own on Saturday.

It was the 17th request for one-on-one talks - where inspectors hope the witnesses could be more candid - which had been denied, inspectors' spokesman Hiro Ueki said.

Iraq has said it is not preventing scientists from meeting privately, but officials suggest the scientists might fear having their words misunderstood if there was no witness.

Security Council update

Also on Saturday, teams from the UN Monitoring, Verification and Inspection Commission (Unmovic) and the International Atomic Energy Agency (IAEA) checked 11 sites for banned chemical, biological or nuclear weapons.

Their findings will be presented to the Security Council on 14 February when Mr Blix and Mr ElBaradei give their latest updates.

KEY DATES

4 Feb - Blair-Chirac talks 5 Feb - Powell to address UN Security Council 14 Feb - Further report from arms inspectors

Next steps in full

US Secretary of State Colin Powell will himself appear before the council on Wednesday with what the Bush administration is calling new evidence that Saddam Hussein is breaking UN rules.

President Bush continues to accuse Baghdad of failing to disarm as demanded by the Security Council.

He believes a resolution passed by the council last November permits the use of force to ensure Iraq has no banned weapons, though he said he was happy for there to be a second, more explicit, ruling.

'Charade'

After discussing the crisis with UK Prime Minister Tony Blair on Friday, Mr Bush dismissed the Iraqi invitation as a ploy meant to "string the inspectors along".

"The idea of calling inspectors in to negotiate is a charade," he said.

Both leaders said time was running out for Saddam Hussein to show he was co-operating with UN demands.

But the Security Council has appeared split over allowing inspectors more time or pushing for action.

Iraq is set to be the focus of talks on Tuesday between Mr Blair and French President Jacques Chirac, who has been one of the leading voices opposing the US-UK approach.

Separately, Greek Foreign Minister George Papandreou, whose country holds the rotating European Union presidency, begins a tour of several Arab countries starting in Syria on Sunday to try to reach a peaceful outcome.