The Bush administration is seeking to derail plans by the chief U.N. weapons inspector to issue another report on Iraqi disarmament to the Security Council in late March, fearing it could delay the U.S. timeline for forcing an early confrontation over Iraq's banned weapons programs.

In a move that diplomats predicted would touch off a potentially divisive battle in the Security Council, the administration plans to press the 15-nation body Thursday to suspend plans for the March 27 report by Swedish diplomat Hans Blix in which he was expected to present a list of disarmament obligations that Iraq must meet before U.N. sanctions can be suspended.

Blix told the council Tuesday that the March meeting is required under a 1999 resolution that created his inspection agency. But his plans have complicated the administration's diplomatic strategy in which it is pointing to the end of this month as the start of an endgame in the six-week-old U.N. weapons inspections program in Iraq.

The administration would like a decision on whether to go to war shortly after a scheduled Jan. 27 presentation by Blix to the council, and U.S. officials said they would ask the body to effectively disregard the 1999 resolution mandating a later report until Iraq fully cooperates with the inspectors. Bush is expected to make a strong case for action against Iraq in his State of the Union address Jan. 28. And he has scheduled a Jan. 31 meeting at Camp David with British Prime Minister Tony Blair, his closest ally on Iraq.

But by announcing he was operating under the assumption that he would produce an additional report two months later, Blix underscored that he is progressing along a much more deliberate timetable. His plan risks undermining the administration's strategy to ratchet up the pressure for a decision on whether to go to war later this month and it raises the prospect that Security Council members, including some U.S. allies, would use it as an excuse to put off a decision until March, at the earliest.

"How can you talk about suspending sanctions or outlining key remaining disarmament tasks when the Iraqis have not complied" with their current obligation to supply the council with a complete declaration on their weapons programs, an administration official said. "They have to first comply. We don't want to reward Iraq."

The issue is pitting the United States and Britain against Russia, France and Syria, which maintain that there are no grounds for rewriting the terms of the 1999 resolution. A diplomat who shares their position said Washington's initiative would remove the council's main incentive for Iraq to cooperate and keep the council in a constant state of crisis. "The council's resolutions shouldn't be flouted, they should be respected," said Fayssal Mekdad, Syria's deputy U.N. ambassador.

China's U.N. ambassador, Wang Yingfan, voiced concern that the standoff could drive a wedge between the council's key members. He pledged to strive to forge a compromise. "We have to work within the Security Council to find a way out" of this dispute, he said. "It's no good for everyone if we have confrontation."

Blix, who is scheduled to pay a final visit to Baghdad on Sunday before presenting his Jan. 27 report, told reporters today that he would urge Iraqi leaders to "provide more evidence" of efforts to develop banned chemical, biological and nuclear weapons. "There is still time, I think, for Iraqis to get themselves out of a very dangerous situation," he said. "I don't think we should ever talk about last chances in the world.

"They have provided prompt access, been very cooperative in terms of logistics," he added. "But they need to do a good deal more to provide evidence if we are to avoid any worse development."

Bush expressed growing impatience Tuesday with the inspection process, saying he is "sick and tired of [Iraqi] games and deception." White House spokesman Ari Fleischer said today that while the president "has made no decisions about whether or not we will go to war," his patience is wearing thin. "Indeed, much of it still depends on Saddam Hussein and whether Saddam Hussein will get the message that time is running out and he needs to actively comply with the inspections and the inspectors," he said.

Defense Secretary Donald H. Rumsfeld said today that the administration is cooperating fully with inspectors.

Under the terms of Security Council Resolution 1441, which was adopted unanimously Nov. 8, the inspectors are required to deliver an assessment of Iraq's cooperation 60 days after the inspections began, which will be Jan. 27. Blix and Mohammed ElBaradei, the head of the International Atomic Energy Agency, have characterized the date as a routine "update."

ElBaradei told reporters in Moscow today that it would be "at least several months" before his team could determine whether Iraq has met its disarmament obligations.

Blix and ElBaradei, noting that the Nov. 8 resolution does not require any further reporting dates, informed the council that they would take their instructions from a December 1999 council mandate, Resolution 1284, that created the Iraqi inspections commission. That resolution requires they provide the council with a new "work program" and a list of "key remaining disarmament tasks" within 60 days after starting their work in Iraq, a period Blix interprets as beginning Jan. 27 and ending March 27.

National security adviser Condoleezza Rice flew to New York on Tuesday to press Blix not to hold the March 27 briefing.

U.S. Ambassador John D. Negroponte has told select council members to back that position, saying that they should not be offering fresh incentives to Iraq when, as the Bush administration sees it, Baghdad has demonstrated an unwillingness to fully cooperate with U.N. inspectors.

Richard Grenell, a spokesman to the U.S. mission to the United States, said: "We feel pretty strongly that we must first solve the initial issues before we turn to the remaining issues."

A senior U.N. diplomat said: "The field of battle is clear. France and Russia believe 1284 is perfectly valid and the timetable should continue, and the United States and the United Kingdom feel it's still valid but its application is contingent on Iraqi compliance."

Staff writer Karen DeYoung contributed to this report.