WASHINGTON — Defense Secretary Donald Rumsfeld warned yesterday that the Bush administration's war on global terrorism would most likely take years to win and cost more lives, calling it an "unusual" conflict that "cannot be dealt with by some sort of massive attack or invasion."

Rumsfeld said for the first time that Operation Enduring Freedom — the Pentagon's new code name for the war, chosen because the original "Infinite Justice" was offensive to Muslims — would require support from "revolving coalitions" of nations, some of which might be willing to support military strikes against terrorists in some countries but not others.

"It will not be an antiseptic war, I regret to say," Rumsfeld said. "It will be difficult. It will be dangerous. And there is ... the likelihood that more people may be lost."

Rumsfeld's remarks continued an administration effort to prepare the public for a difficult, costly and sustained anti-terrorism campaign that is likely to suffer deadly setbacks as well as secret successes.

"There is not going to be a D-Day, as such, and I'm sure there will not be a signing ceremony on the Missouri, as such," he said. He referred to the final Allied push in Europe in June 1944 and the signing of surrender papers aboard the USS Missouri in 1945.

In response to a question, Rumsfeld also said Pentagon officials had no plans to lie to the news media as part of any disinformation campaign designed to mislead Saudi exile Osama bin Laden and members of his al-Qaeda network, which the United States blames for orchestrating the attacks against the World Trade Center and the Pentagon.

"I don't recall that I've ever lied to the press, I don't intend to, and it seems to me that there will not be reason for it," Rumsfeld said.

But Rumsfeld continued to warn against news leaks, promising to keep a tight lid on classified information.

Rumsfeld spoke during a frenetic day at the Pentagon, which began with an announcement that he had given the uniformed military services "stop-loss" authority to retain personnel involuntarily beyond their scheduled retirement dates. Such authority, used extensively during the Persian Gulf War, was last granted in 1999 during NATO's air campaign over Kosovo.

Only the Navy announced an immediate plan to stop personnel from retiring, saying it intends to keep 10,500 people in 11 critical specialties from leaving.

Later, the Pentagon announced 1,661 additional members of the National Guard and reserves had been called to active duty, bringing the total to about 14,000 since the terrorist attacks. President Bush authorized the Pentagon to call as many as 50,000 to active duty.

Also, officials at Fort Campbell, Ky., said about 200 soldiers from the 101st Airborne Division were sent to each of two chemical-weapon storage facilities in Kentucky and Indiana to augment security. A spokeswoman said there had been no specific threat against either place.

Rumsfeld said even more people would be called up to active duty. But he said there had been no consideration of re-activating a draft: "I don't foresee a need to do that."

With U.S. air, land and sea forces positioning themselves within striking distance of Afghanistan, the broad outlines of a military campaign to destabilize the country's ruling Taliban and root out bin Laden are beginning to take shape.

The campaign has likely already begun, with covert intelligence gathering and elite commando units quietly working with opposition forces in the country. Next may come nighttime bombing raids on the capital of Kabul and on the southern city of Kandahar, where the Taliban has some of its headquarters, former Pentagon officials and military analysts said.

And while administration officials indicate Afghanistan will be the primary target of military strikes, military action is not likely to end there.

The buildup of conventional forces in the region — enough to fight what the Pentagon calls a "major theater war" — is being put in place to back initial strikes within Afghanistan, and to deter others in the region, such as Iraq's Saddam Hussein, from using the opportunity to strike out at the United States.

The concentration of U.S. military might in the region gives military planners a wide range of options, and should ideally allow the military to move swiftly and change tactics in accordance with what is known about the terrorists' changes.

Information from The Washington Post, The Associated Press and the Los Angeles Times is included in this report.