The Pentagon is pressing on with preparations for possible war against Iraq, but it is not yet clear that an attack to force Saddam Hussein to disarm would begin this winter as once widely expected.

If Iraq refuses to accept a U.N. resolution restarting weapons inspections, a U.S.-led attack could take place by December or January. But, for now, the U.N. Security Council has failed to agree on such a resolution.

And if Saddam agreed to cooperate with U.N. weapons inspections, at least initially, that could delay military action beyond winter and spring, which are considered the most suitable times for conducting war in Iraq.

In the meantime, President Bush spoke by telephone Wednesday with Turkish President Ahmet Necdet Sezer, whose permission the United States would need to use Turkey's Incirlik Air Base in any assault on Iraq.

"They discussed cooperation on Iraq,'' White House press secretary Ari Fleischer said, without elaborating.

Victoria Clarke, spokeswoman for Defense Secretary Donald H. Rumsfeld, said Wednesday the Pentagon was moving ahead as scheduled to position forces and equipment that could be used in battle against Iraq.

"We're moving people and resources that we think are appropriate,'' she said, adding that no decision has been made to go to war.

Senior U.S. military officials said Tuesday they are ready to act whenever President Bush decides the time is right.

Gen. Richard Myers, chairman of the Joint Chiefs of Staff, was asked at a Pentagon news conference whether he was concerned that Iraq has the luxury of time to prepare its defenses against an American invasion.

"I can tell you we're postured in a way that that will not be a problem,'' Myers replied. He said that in strictly military terms, the passage of time can aid both the attacker and the defender.

"The longer you wait, obviously, an adversary has time to prepare — but so do you, to prepare for the consequences,'' he said.

Secretary of State Colin Powell went on television again Tuesday to show resolve to the American people and to threaten Saddam.

"We have demonstrated repeatedly in recent years we will fight a conflict, if it comes to a conflict, with sophisticated weapons, with precision weapons in a way that minimizes loss of civilian life,'' Powell said on "The Oprah Winfrey Show.''

"Will there be some loss? Of course,'' he said. "There always is. That's why war should be avoided.'' But to put off action, Powell said, "just leads to the inevitability of Saddam becoming more dangerous, the Iraqi regime becoming more dangerous, in the months and years ahead.''

The Navy already has two aircraft carrier battle groups within striking range of Iraq and may have four there by December; the Air Force has more than 200 warplanes based in the Persian Gulf area; the Army has several thousand soldiers in Kuwait, and there are a few thousand Marines aboard ships in the region.

If U.S. military action were pushed to summer or beyond, conditions could be more difficult for the invading forces. The gear soldiers wear as protection against chemical or biological weapons, for example, is much more difficult to operate in during the blistering heat of an Iraqi summer. But the heat would not help the Iraqis either.

"On balance, people would prefer to fight during the spring, but you can make a lot of adaptations,'' said Anthony Cordesman, who has studied and written extensively about Iraq's decade-long war with Iran and the 1991 Gulf War.

"It just doesn't matter,'' he said, because U.S. forces have such overwhelming advantages over the Iraqis.

Bush said Monday he doubts Saddam will reverse himself and accept a proposed U.N. Security Council resolution requiring him to provide unlimited and unimpeded access to suspected weapons areas. If he does, Bush said, "that in itself'' would indicate the administration had reached its goal of changing the regime without resorting to war.

Ivo Daalder, a Brookings Institution foreign policy expert and a National Security Council staffer during the Clinton administration, estimated there is a one-in-three chance Saddam will acknowledge he holds some banned weapons of mass destruction and let U.N. inspectors destroy them.

In that case, war could be avoided for many months — or possibly averted altogether, Daalder said.

Frank Ronald Cleminson, a Canadian member of the U.N. Monitoring, Verification and Inspection Commission, said Tuesday that if Iraq allowed inspections to run their course, they could be completed in 10 months.

More likely, the matter will come to a climax earlier.

Under a U.S. draft resolution not yet accepted by other members of the Security Council, Saddam would have to submit a detailed declaration of the status of his weapons programs within 30 days of the resolution's passage.

That could be a trigger for war if Saddam declared — as he has in the recent past — that Iraq has no such weapons.

If Saddam admitted having some banned weapons and allowed U.N. inspectors to destroy them, then the question for Bush would be whether his admission was sufficient to withdraw the threat of war.