United Nations weapons inspectors began a crucial mission in Iraq on Monday, and U.N. Secretary-General Kofi Annan warned Baghdad the only way to avoid war was to cooperate with them. Looking for nuclear, biological or chemical weapons, the group of inspectors were due on Wednesday to begin their first search for four years in Iraq, which President Bush has threatened with war if it does not disarm.

"I hope the government of Iraq will fully cooperate with the inspectors and respect its obligations unreservedly. That is the only way to avoid conflict in the region," Annan told a news conference in Paris.

Iraq, which must make a formal declaration by Dec. 8, denies it has weapons of mass destruction. But chief U.N. weapons inspector Hans Blix said Baghdad had to come clean about its arms programs, saying earlier weapons declarations "did not give a full account."

Reflecting the Bush Administration's hard-line against Iraq, the United States forced the U.N. Security Council on Monday night to delay for nine days the Iraq oil-for-food plan, which is usually renewed for six-month periods, to give council members more time to negotiate.

The plan allows Iraq to sell oil and covers food, medicine and a host of civilian supplies to ease the impact of U.N. sanctions imposed after Iraq's 1990 invasion of Kuwait.

The United States wants only a three-month renewal and has linked the plan to expanding a U.N. list of items that have dual military and civilian uses. Among the goods Washington wants banned are atropine injectors and the large quantities of the drug atropine, which can be used to combat nerve gases.

British Prime Minister Tony Blair also warned President Saddam Hussein on Monday not to play a game of "hide and seek" in the hunt for illicit armaments -- a search that arose from the cease-fire accord in the 1991 Gulf War. The U.N. Security Council on Nov. 8 adopted a tough new resolution giving Iraq one more chance to disarm.

Blair said a false declaration would constitute a "material breach" of the Nov. 8 resolution 1441 but that it was up to the weapons inspectors to pass judgment. In contrast, the Bush administration has indicated it could make the decision, without input from the inspectors, and then prepare for war.

BLIX REPORTS TO THE UN SECURITY COUNCIL 

Blix, just back from a trip to Baghdad, told the Security Council Iraq would have to provide convincing evidence to prove it no longer had any weapons of mass destruction.

The Swedish chairman of the U.N. Monitoring, Verification and Inspection Commission, known as UNMOVIC, also told reporters: "They maintained the position that they have no weapons of mass destruction. I said they should look into their stores and stocks."

"The production of mustard gas is not exactly the same as the production of marmalade." he also said.

Iraq has to submit a declaration to the council next month, listing all its weapons programs as well as materials that could be used as ingredients for nuclear, chemical, biological and ballistic arms. Blix said Iraqi officials raised concerns about the declaration but "I had the feeling they were going to try to put up a very substantial report."

POWELL DISMISSES BAGHDAD'S ANGRY LETTER TO UN CHIEF

Secretary of State Colin Powell noted Iraqi authorities made public on Sunday an angry letter to the United Nations over the resolution's terms but said their December report was key.

"We are now focusing on the 8th of December, when the declaration is due. The letter they sent in over the weekend was certainly not indicative of a cooperative attitude on their part."

ELBARADEI SAYS IT'S UP TO BAGHDAD TO AVERT WAR

In Cairo, Mohamed ElBaradei, head of the International Atomic Energy Agency (IAEA), which has experts on the U.N. inspection team, told reporters that if inspectors had free access and found no arms, war would be averted. "If we can give a positive report, the inspections will be an alternative to war, not a precursor to war," he said.

He added, after a meeting with Arab League Secretary-General Amr Moussa, "The real test will be when the inspections start."

The new U.N. resolution obliges Baghdad to allow the inspectors to peer into every corner of the country. The inspectors must give their first report to the U.N. Security Council by January 27.

INSPECTORS ARRIVE IN BAGHDAD AHEAD OF WEDNESDAY'S FIRST INSPECTION MISSIONS THIS ROUND

"We have had a lot of promises of cooperation (from Iraq) and we believe that is a good start, but we have suspicious minds. We are here to test cooperation," Melissa Fleming, IAEA spokeswoman told reporters in Baghdad.

An advance team of U.N. logistics experts has been in Iraq since last week, preparing the ground for the new mission. U.N. inspectors left Iraq in 1998, accusing Baghdad of failing to cooperate. The United States then mounted air strikes.

In another incident on Monday that U.S. officials have said could be such a breach of the resolution, an Iraqi military spokesman said anti-aircraft batteries opened fire at U.S. and British planes over the south of the country.

Most of the international community disagrees with the tough U.S. stance about the Iraqi firing on Western warplanes patrolling "no-fly" zones set up after the Gulf War.

PHOTO CAPTION

Chief Weapons Inspector Hans Blix exits the Security Council chamber at United Nations in New York November 25, 2002. United Nations weapons inspectors began a crucial mission in Iraq, and U.N. Secretary-General Kofi Annan warned Baghdad the only way to avoid war was to cooperate with them. (Chip East/Reuter