The United States moved closer to a possible war with Iraq as the Bush administration on Monday suggested a decision could come as early as next week.

To bolster its case, the United States intends to provide the inspectors with additional evidence to support its claim that President Saddam Hussein has been moving and hiding thousands of chemical and biological weapons in palaces, mosques and private homes.

A senior Bush adviser, speaking on condition of anonymity, said Secretary of State Colin Powell will unveil next week "broad evidence" against Saddam, including new information about his ties to Al Qaeda, his weapons of mass destruction program and his efforts to deceive the world community by hiding his deadly arsenal beneath the ground and in mobile facilities.

Some officials are expecting President Bush to have Powell deliver the material at the United Nations, but details were still being worked out Monday. The decision comes as Democrats and anxious U.S. allies intensified demands for proof that Saddam possesses weapons of mass destruction.

Bush and his senior advisers would not specify when the U.S. might begin a military showdown to force Iraq to disarm. But Powell said the tug-of-war with Saddam must end.

"What we can't do is just keep kicking the can down the road in the absence of a change in policy and attitude" in Baghdad, Powell said at a State Department news conference, even though he consented to additional U.N. inspections.

"We will have our discussions and consultations this week, and then we will announce [our] next steps at an appropriate time," he said.

The Pentagon pushed ahead with war preparations that would position more than 150,000 troops and four aircraft carrier battle groups, each with more than 70 warplanes, in the Persian Gulf region by the end of February.

In a significant step, the Pentagon concluded an arrangement with the Turkish government to permit up to 20,000 U.S. troops to use bases in Turkey for a potential ground invasion into northern Iraq, a senior Defense Department official said. Turkey, a valued ally in the 1991 U.S.-led war with Iraq to liberate Kuwait, had taken an ambivalent stance this time.

To facilitate the flow of war material to the Gulf, 13 more cargo ships from the Transportation Department's Ready Reserve Force fleet have been activated, the department announced Monday. They join 19 other ships already activated.

The Ready Reserve Force ships are operated by American merchant mariners who volunteer for the missions. The fleet augments cargo ships of the Navy's Military Sealift Command.

The administration's strategy calls for agreement to possibly a few more weeks of inspections as Powell, U.N. Ambassador John Negroponte and other American diplomats lobby the 14 other members of the Security Council to implement the "serious consequences" the council threatened Iraq with in November.

Germany opposes going to war. France, Russia and others are skeptical that a case for war has been made.

Bush, meanwhile, will try to prepare the nation for war in his State of the Union address Tuesday night, but will withhold announcement of any decision on an attack that many members of Congress oppose.

On Capitol Hill, Senate Democratic leader Tom Daschle of South Dakota said Monday, "If we have proof of nuclear and biological weapons, why don't we show that proof to the world -- as President Kennedy did 40 years ago when he sent Adlai Stevenson to the United Nations to show the world U.S. photographs of offensive missiles in Cuba?"

Rep. Nancy Pelosi of California, the House Democratic leader, urged, "Let's exhaust every diplomatic remedy before we send our troops."

To bolster the U.S. case, the United States intends to provide the inspectors with additional evidence to support its claim Saddam has hidden thousands of chemical and biological weapons in palaces, mosques and private homes.

One Iraqi scientist, for instance, has kept from the inspectors a 3,000-word document on Iraqi weapons procurement, a senior U.S. official said Monday.

Top Democrats on the House Armed Services Committee, Reps. Ike Skelton of Missouri and John M. Spratt Jr. of South Carolina, asked Bush in a letter to continue the U.N. arms search "so long as it holds reasonable promise of success" and might build allied support.

With anxious U.S. allies also intensifying their demands for proof that Saddam possesses weapons of mass destruction, Powell acknowledged "there are disagreements."

"There are some who are satisfied with passive cooperation at this point," he said.

But the U.N. resolution unanimously approved last November was not about "passive cooperation," and chief U.N. weapons inspector Hans Blix on Monday "made it rather clear that he is not getting the kind of cooperation, and Iraq has not made the fundamental choice it has to make that it is going to be disarmed," Powell said.

And so, he said, "we are getting closer and closer to the point where the Security Council is going to have to look at the options that it anticipated."

The Associated Press contributed to this report.