The moment for military action against Iraq is almost here, Defense Secretary Donald H. Rumsfeld said Friday as he traveled to Europe to push forward the American case against Saddam Hussein.

Rumsfeld's trip coincided with an ever-increasing buildup of U.S. forces in the Persian Gulf area. In a few days, there will be 150,000 American troops in the region — enough to launch at least the first stage of an invasion.

"This is a critical time," Rumsfeld told reporters traveling with him from Washington. "Anyone who looks at what's taking place can see that momentum is building with respect to efforts to get Iraq to disarm."

The defense secretary's comments echoed President Bush's statement Thursday that "the game is over" for Saddam.

Later in the day, at the Aviano air base in northern Italy, Rumsfeld praised American service members and their families who had gathered to hear him speak.

"You are what stands between freedom and fear," the defense secretary said, "between our people and an evil that must not be allowed to win. The hopes of mankind depend on your success."

"Shortly after Sept. 11," Rumsfeld added, "President Bush made a promise to the nation: We will not waver, we will not tire, will not falter and will not fail. You are the ones delivering on that promise."

On Thursday, the Army's 101st Airborne Division — the famed "Screaming Eagles" — confirmed they had received an order to deploy their air assault forces from Fort Campbell, Ky., to the Persian Gulf.

More than 110,000 U.S. forces already are in the Gulf area — nearly half in Kuwait, where the main ground attack into Iraq would start.

Rumsfeld met with Italian Prime Minister Silvio Berlusconi and Defense Minister Antonio Martino and was then visiting U.S. troops at Aviano air base in northern Italy. From Italy he was flying to Munich for an annual security policy conference of European and Asian defense officials.

After the meeting, Martino said at a news conference with Rumsfeld that his government shares the U.S. position on Iraq.

"It would be a terrible, terrible blow to the credibility of the United Nations" if Saddam were to be allowed to continue defying the resolution on disarmament, he said.

Rumsfeld reiterated the administration's warning to Iraq against using chemical or biological weapons in the event of a war.

"They would be well advised not use those weapons," Rumsfeld told reporters. "In the event they do, they will wish they hadn't."

He declined to discuss whether the United States would consider using nuclear weapons in retaliation.

Rumsfeld said he hoped to reinforce the central message of Secretary of State Colin Powell's presentation to the U.N. Security Council on Wednesday: that Iraq is deceiving U.N. weapons inspectors, not cooperating with them to account for the weapons of mass destruction he is accused of holding.

"The one thing that it seems to me needs to be put in better focus is the issue of time," Rumsfeld said in the interview aboard his Air Force jet. "One could make a very strong case that time is desirable if in fact Iraq were cooperating. But the idea that it takes a long time to determine if Iraq is cooperating obviously answers itself — it doesn't take a long time to determine."

Some European allies, including Germany and France, believe the U.N. inspectors should be given more time, but the Bush administration insists that Iraq has already made clear it does not intend to give up any banned weapons. This difference of view has caused a rift in the U.S.-European alliance.

The Munich session will give Rumsfeld a chance to shore up relations with European allies who have felt slighted by some of his recent remarks — especially France and Germany, which oppose early military action against Iraq.

Rumsfeld added to the strain on Wednesday when, during testimony before the House Armed Services Committee, he lumped Germany in with longtime U.S. adversaries Cuba and Libya.

A panel member asked Rumsfeld what kind of cooperation the Bush administration could expect from other nations in the event of a war. He listed several he considered supportive and others he thought might come around to backing the operation.

"And then there are three or four countries that have said they won't do anything. I believe Libya, Cuba and Germany are the ones that I have indicated won't help in any respect," Rumsfeld said.

Germany and the United States have been close allies for decades. Most of the American troop presence in Europe is based in Germany, and portions of the German air force train year-round in the United States.

The tensions with Germany began last year after Chancellor Gerhard Schroeder's governing coalition won national elections by opposing U.S. military action in Iraq, and a top German official compared President Bush's tactics to those of Hitler.

Asked Friday about Rumsfeld's comment, German Foreign Minister Joschka Fischer said how much Germany owes to the United States for its democracy and, more recently, unity. He said he shared the concern for terrorism in the world and also in Germany. About the specific remark, he said, "Well, that's Rumsfeld."

He said no meeting between the two was scheduled while they were both in Italy.

The Associated Press contributed to this report.