Iraq invited the chief U.N. inspectors back to Baghdad on Thursday for more talks on ways to verify Iraqi disarmament and deflect charges that Saddam Hussein's government is not cooperating fully with them.

The surprise invitation for Hans Blix and Mohamed ElBaradei to make their second trip to Iraq in a month came as President Bush warned he would give diplomacy "weeks not months" to prevent war.

Iraq sought the new talks ahead of Blix and ElBaradei's next crucial report to the U.N. Security Council on Feb. 14. There was no immediate response from the two chief inspectors.

Blix, who is in charge of chemical and biological inspections, repeated Thursday that he needs more evidence of disarmament from the Iraqis. But it was unclear whether any evidence Baghdad might offer in such talks would be enough.

"They must take the questions seriously that were posed in the report," Blix said in New York. "We would like to have responses to those questions."

In announcing the invitation, the Iraqi Foreign Ministry said the talks, to be held before Feb. 10, would be aimed at "boosting cooperation and transparency [and] jointly discussing methods of disarmament verification."

Blix and ElBaradei held two days of talks in Baghdad on Jan. 19-20 before they delivered a report Monday to the U.N. Security Council on progress in inspections. Blix toughly criticized Iraq in the report, saying it had not genuinely accepted the need to disarm.

Iraq's U.N. Ambassador Mohammed al-Douri delivered the invitation to Blix late Thursday and spent an hour with him discussing Baghdad's seven-page response to Blix's report. ElBaradei, head of the U.N. nuclear agency, was returning to Vienna from New York and was expected to receive his invitation on Friday.

Al-Douri said Baghdad sought the new talks to avoid any "misunderstanding" with the inspectors.

"If we reach a better understanding and agreement on several issues, that will constitute a major achievement," he said.

Talk of a war that would short-circuit the inspection program dominated top-level meetings in Washington.

In an Oval Office session with Italian Premier Silvio Berlusconi, Bush said he will not wait long to act against Saddam, even if the United Nations refuses to back his actions.

The U.S. and British governments say they will take military action against Baghdad if, in their view, it fails to disarm under U.N. resolutions prohibiting the Iraqis from engaging in chemical, biological and nuclear weapons programs.

Such a U.S. offensive against Iraq might leave a huge number of civilian casualties, a 16-member team of American humanitarian specialists said in Baghdad after completing a 10-day survey throughout Iraq.

They cited a confidential U.N. document projecting a worst-case scenario of up to 500,000 Iraqis killed, wounded or stricken by disease, particularly if U.S. bombs target Iraq's electricity grid, crippling water, sanitation, public health and food distribution systems.

The disruption of water and sewage systems after the Americans bombed the power grid in the 1991 Gulf War was blamed for thousands of subsequent Iraqi deaths by disease in the 1990s. International trade sanctions, spearheaded by Washington, also eroded Iraqi health and other living standards.

In his State of the Union address Tuesday, Bush said an American invasion would "bring to the Iraqi people food and medicines and supplies and freedom."

On Thursday, Iraq's health minister, Omed Medhat Mubarak, rejected that.

"How can President Bush improve health conditions of Iraqis when America was the reason behind the deterioration in the health of Iraqis from all walks of life?" he asked.

In other developments Thursday:

-- Weapons inspection teams took a step toward long-term monitoring in Iraq, installing the first equipment to sample the air for clues to banned weapons work.

-- Two more Iraqi experts refused to grant secret interviews to U.N. investigators in the hunt for Iraq's alleged weapons of mass destruction. To date, no Iraqi is known to have submitted to an interview without the presence of an Iraqi government official or other witness.

The refusal of Iraqi scientists to submit to private interviews with U.N. arms monitors has been one trouble spot in the inspections, which resumed in November after a four-year gap.

Iraqi officials say that under an agreement reached Jan. 20 with the chief U.N. inspectors, they are encouraging scientists to submit to unmonitored questioning. But they all feel that having a witness would protect them against possible later distortion of their answers, the officials say.

The U.N. inspectors, on the other hand, believe scientists would be more candid in interviews without representatives of Iraq's authoritarian government listening in.

After their talks Jan. 19-20, the inspectors and Iraqi officials announced a 10-point agreement to clear up some procedural roadblocks to more effective inspections.

A week later, however, Blix reported to the Security Council that, although Baghdad had been cooperative on practical matters, it was still not offering sufficient evidence to clear up old discrepancies, by verifying its destruction of some chemical and biological arms or components.