DAVOS, Switzerland. Jan. 26 -- Secretary of State Colin L. Powell said in his clearest terms yet today that he expects Iraqi leader Saddam Hussein may need to be disarmed by force. He called on world leaders to stand together in a "great coalition" to prevent war and, if necessary, to fight one.

The evidence that Hussein will continue to defy the U.N. Security Council is strong, Powell told a gathering here of the World Economic Forum. In forceful terms, he said Hussein has failed to account for his weapons programs and poses a grave danger. International weapons inspectors, he said, will not be able to locate and remove munitions without Iraqi compliance.

To people who urge taking months more to allow the U.N. inspector to work, Powell said, "It is not a matter of time, it is a matter of telling the truth." He said the United States would not rush to judgment when a U.N. inspectors' report is delivered Monday, "but clearly time is running out."

Powell made his most dramatic comment in response to a question about how Sept. 11 had affected him personally. He spoke with emotion about the realization that the United States was at war, the terrorist enemy was real and the Bush administration would have to act, even on a day "when our anxieties would well up and our fears would well up."

"We are probably approaching one such moment now," Powell said. "We will have to take that next step, and history will judge us as to whether or not we have the strength, the fortitude and the willingness to take that next step."

Chief U.N. weapons inspector Hans Blix is expected to report Monday to the Security Council that the Iraqi government continues to refuse to take an active role in the inspections process. The council will debate the matter late in the week amid strong signs that a formal decision about the use of force is at least several weeks away.

On Saturday, Hussein's top adviser on weapons issues said the military build up in the region makes war almost inevitable. Gen. Amir Saadi told American reporters that Iraq already believes it is doing all it can to prevent the military conflict. He said no matter what Iraq does, the Bush administration will ask for more.

In Davos, Powell sought to answer critics, particularly in Europe, who question U.S. motives and the pace of the administration's anti-Hussein effort. His trip followed a week when Security Council members France, Germany and Russia made very public their view that the Americans are moving too quickly.

The Bush administration has advertised that it is prepared to act without U.N. approval, if necessary, to disarm Iraq and overthrow Hussein's dictatorship. But with Powell taking the diplomatic lead, the administration is hoping to assemble a broader coalition that can intimidate the Iraqi leader, inspire a coup against him or defeat him if he resists.

Powell's speech is part of an administration campaign to bolster public opinion at home and abroad. It began in earnest last week with prominent speeches by his deputy, Richard L. Armitage, and deputy defense secretary Paul Wolfowitz. It continues Tuesday night with President Bush's State of the Union address, where Powell said Bush would lay out a case against Iraq but not deliver any dramatic announcements.

At an annual conference of opinion leaders whose theme this year is "Building Trust," Powell responded to doubts about U.S. foreign policy.

He said the United States can be trusted to use its enormous economic, political and military power wisely. In an effort to repair recent damage, he pledged to work closely with Europe, "home of our closest friends and partners."

Powell said pointedly, however, that the 15 Security Council members who unanimously threatened "serious consequences" against Iraq in November knew they would be asked to approve military force if Hussein fell short.

He challenged the countries not to shy away from a confrontation.

"There was no confusion on this point. Everybody knew what that meant," Powell said. He pledged the administration would reveal more of its evidence about Iraq's weapons programs, but called the existing public case "persuasive." Only those who oppose using force entirely could disagree, he suggested.

Powell said Hussein has "clear ties to terrorist groups including al Qaeda," and said the longer the international community waits, the greater the chance that Hussein will share his weapons and technology or use them again. Hussein has used poison gas on his own people and on neighboring Iran.

"The support of U.S. intelligence and the intelligence of other nations can take the inspectors only so far," Powell said. "Without Iraq's full and active cooperation, the 100 or so inspectors would have to look under every roof and search the back of every truck in a country the size of California to find the munitions and programs for which Iraq has failed to account."

When a representative of Amnesty International asked Powell whether the potential benefits of an invasion of Iraq were worth risking a humanitarian calamity in Iraq and the region, he replied that Iraqis are suffering now and post-Hussein Iraq would offer greater opportunities to them.

Powell again defended the use of military force in response to a question from George Carey , the former Archbishop of Canterbury, who asked about he relative merits of "hard power," or military force, in contrast to "soft power," such as economic assistance, international agreements or the force of example.

"There comes a time when soft power or talking with evil will not work, where unfortunately hard power is the only thing that works," Powell said.

"There are still leaders around who will say you do not have the will to prevail over my evil, and I think we are facing one of those times now," he said.

On his way to Switzerland aboard an Air Force jet Friday night, Powell described to reporters his current thinking about Iraq. He is hoping the views of the Security Council governments develop in a similar way.

Powell said it was important last year to give Hussein "one last chance" to meet U.N. requirements and to allow inspectors to oversee the process. He pushed for the "serious consequences" warning in case of Iraq's "continued intransigence and misbehavior and lying and cheating and deceiving."

"So my position has been, ‘Let's try to solve this peacefully,'" Powell said. "If Iraq is not willing to participate in a way that solves it peacefully, then time will run out on Iraq and Iraq will pay serious consequences."