UNITED NATIONS -- The United States headed for a major diplomatic battle in the UN yesterday as Canada and other countries urged Washington to step back from war and give weapons experts more time to search Iraq for nuclear, chemical and biological weapons.

"They should be given the time to do their work and all of us, the council and the assembly, must realize that time will be necessary, a reasonable amount of time," Secretary-General Kofi Annan said after chief inspector Hans Blix presented the 15-member UN Security Council with a progress report on his team's first 60 days in Iraq.

"I'm not saying forever, but they do need time to get their work done and I suspect the council will allow that to be done."

With domestic support wavering and jittery markets falling further nearly every day, Washington warned that its patience for diplomatic manoeuvres was running out. U.S. President George W. Bush is to address Americans tonight, and Iraq is expected to be a focus of that speech.

"Iraq's time for choosing peaceful disarmament is fast coming to an end," U.S. Secretary of State Colin Powell warned yesterday, after Dr. Blix spoke to the Security Council. "The issue is not how much more time the inspectors need to search in the dark. It is how much more time Iraq should be given to turn on the lights and to come clean. The answer is: not much more time."

The UN report says inspectors have found neither evidence of nuclear weapons nor major stocks of biological weapons or chemical weapons. But it warns that caches of such deadly weapons are still unaccounted for, and criticizes Baghdad for offering less than the full co-operation it promised two months ago, when it allowed UN weapons inspectors back into the country.

"Iraq appears not to have come to a genuine acceptance, not even today, of the disarmament that was demanded of it," said Dr. Blix, who heads the UN Monitoring, Verification and Inspection Commission.

Dr. Blix said 6,500 chemical bombs that could hold deadly VX nerve gas remain unaccounted for.

"We promise to be more forthcoming in the future, responding to all their needs," he said in an interview on CBC News.

Dr. Blix said 6,500 chemical bombs that could hold deadly VX nerve gas remain unaccounted for, and that the discovery of a small cache of 122 mm chemical rocket warheads in a bunker southwest of Baghdad could be "the tip of a submerged iceberg."

The discovery "does not resolve, but rather points to, the issue of several thousands of chemical rockets that are unaccounted for," he said.

He did not say how much extra time might be needed, but said he felt pressure to achieve disarmament within a "reasonable" amount of time.

Mohamed ElBaradei, director-general of the International Atomic Energy Agency, was less critical.

Still, he said that during his team's hunt for an Iraqi nuclear-weapons program, he concluded that the Iraqi government is not being "pro-active" enough in providing access to documents and government scientists.

In Ottawa, Prime Minister Jean Chrétien said Canada believes the inspectors need more time, a position restated by Canadian diplomats.

In interviews, envoys based in Ottawa and at the UN insisted that the inspectors' preliminary reports are not enough alone to make Washington's case for military action.

"People are not yet persuaded that a war is the correct response to the circumstance," a senior diplomat said.

"I'd have to say there's substantial skepticism about the necessity of doing this -- a willingness to be good multilateralists, but on the other hand, no great enthusiasm," he added.

Indeed, the days ahead could see a significant battle within the Security Council, whose support Mr. Bush needs if he is to win a UN resolution supporting military action.

While Washington continues to suggest that it could wage a war against Iraq alone or with a few allies, many UN diplomats believe U.S. public opinion will push Mr. Bush to seek the world body's blessing.

"If you ask some of the hardheads in Washington, they would dispense with the UN immediately," a diplomat said. (Tens of thousands of U.S. and British troops are already massing in the Persian Gulf region, and Washington won approval yesterday to use Turkish bases for a possible ground invasion.)

"But others are looking at the polls, and they don't seem as anti-UN as the administration might expect."

David Malone, president of the New York-based International Peace Academy, said he expects Mr. Bush to try to forge a Security Council coalition that favours a resolution allowing military action. Washington would need to win the vote of nine of the 15 members and avoid a veto from any of the five permanent members.

Mr. Malone said Dr. Blix's report was tougher on Baghdad than many expected, making such a coalition possible.

"He has given the Iraqis zero wiggle room," Mr. Malone said. "I was surprised by the very grim tone adopted by Blix. He made clear that while the Iraqis have done the minimum, they have not been pro-active."

The Security Council will meet tomorrow in a closed session to discuss what it heard yesterday. But sharp divisions are already clear. "We share the view of many that this process has not been completed and more time is needed," said Zhang Yishan, deputy UN ambassador for permanent member China.

Russian Ambassador Sergey Lavrov, whose country also holds a veto, said Moscow strongly supports calls "for inspections to continue," and French Ambassador Jean-Marc de La Sablière said inspectors might need several weeks or even months.

That leaves only Britain clearly in the U.S. camp.

Mr. Malone said Russia and China are likely to end up abstaining, and France, perhaps the toughest sell, may back down from using its veto because doing so would force Washington to act unilaterally, exposing the UN's weakness and hurting France's ability to use the world body as an international stage.