Hans Blix, the chief United Nations weapons inspector in Iraq, will tell Security Council members today that he is "not impressed" with Baghdad's cooperation with inspections since his last report in late January, U.N. officials said. But officials said that Blix will stop short of saying Iraq has been totally noncooperative.

Blix's presentation is unlikely to resolve the deep disagreement between the United States and other members over whether inspections should continue, or whether the council should turn to consideration of disarming Iraq with military force. President Bush yesterday issued a fresh challenge to the council to "rise to its responsibilities," while other powerful members insisted they would not be bullied into war by the United States.

Secretary of State Colin L. Powell and the foreign ministers of the other four permanent council members will attend Blix's presentation, along with those of a number of the other 10 members. Permanent members France, Russia and China, along with Germany, the current council president, have advocated continuing the inspections. The Bush administration has made clear that it views the meeting as a final prelude to a war decision.

U.N. officials said Blix plans to "welcome" the establishment of an Iraqi commission of inquiry to look for documents that could back up claims that chemical and biological weapons have been destroyed along with the precursor chemicals to build them.

He will indicate that Baghdad has made some progress in arranging private interviews with weapons scientists and technicians, but will point out that only three of a number of requested interviews have so far taken place outside the presence of Iraqi government minders. Blix will note that Iraq still has not unconditionally agreed to U-2 surveillance plane overflights, and will indicate that documents recently turned over by Baghdad have provided little pertinent information.

But the most potentially explosive issue Blix will discuss is Iraqi production and deployment of missiles with ranges beyond a limit set by the United Nations, and its possession of hundreds of prohibited engines to power them. Officials said last night that Blix was still wrestling with whether to use his own authority to order Iraq to destroy them, or to simply report the missile violations to the council and await its decision on what to do about them.

Under his council mandate, Blix is authorized to inform Iraq in writing that prohibited weapons have been found, and order their destruction at a time and place of his choosing. Iraqi refusal to destroy the missiles would constitute the most direct and visible defiance of the United Nations since inspections resumed in late November after a four-year hiatus.

Ironically, while Powell last week presented the council with evidence of alleged concealment of weapons of mass destruction, both the missiles and the engines were among the few new items reported by Iraq in a Dec. 7 declaration presented to the council. The Iraqis said they had slightly exceeded the limit in test firings. The missiles were among the first items inspectors investigated. Blix halted all further testing and placed those that had already been deployed with Iraqi military units, as well as the prohibited engines, under seal so they could not be moved.

When he reported on the missiles to the council last month, Blix said he was still assessing whether their range exceeded a 150-kilometer (93-mile) limit imposed by U.N. disarmament resolutions that followed the 1991 Persian Gulf war. On Wednesday, a team of international experts helping with the assessment reported that the liquid-fueled Al Samoud 2 rocket, one of two ballistic missiles under inspection, was capable of exceeding the allowed range. Experts were divided on the second rocket, the solid-fueled Al Fatah.

Blix plans to report that the Al Samoud 2 is "clearly capable" of going beyond the 150-kilometer limit, and that the 380 missile engines purchased by Iraq over the past several years can power missiles "significantly longer than allowed," one official said. The ground-to-ground missiles in question would be a first line of Iraqi defense should the United States and its allies launch a land invasion of Iraq.

Anthony H. Cordesman, senior fellow at the Center for Strategic and International Studies and co-director of its Middle East Studies Program, said yesterday that Iraq has "successfully scaled systems up" by taking short-range missile systems and converting them to longer range, either by using multiple engines on a single missile or limiting the size of the payload.

Cordesman said that should war break out, Iraqi President Saddam Hussein could be expected to use Al Samoud 2 and Al Fatah missiles that have already been deployed against the rear areas of any attacking U.S. forces.

In a television interview in Rome yesterday, where he was meeting with Pope John Paul II, Iraqi Deputy Prime Minister Tariq Aziz said that Iraq was "no threat to anyone," and no longer had the long-range capabilities it used to launch Scud missiles at Israel during the 1991 Gulf War.

Blix may also raise questions about casting chambers that are used to produce the solid fuel for the Al Fatah. The chambers had been destroyed by previous U.N. inspectors during the 1990s, but Blix's U.N. Monitoring, Verification and Inspection Commission reported last month that they had been reconstituted. Blix may, on his own, order them destroyed.

Blix has been under strong U.S. pressure this week to emphasize the negative aspects of his findings, on grounds that Security Council Resolution 1441, passed in November, was Iraq's "final opportunity" to "fully" disarm and comply with inspections. Anything short of full cooperation, the administration contends, is grounds for declaring Iraq in "material breach" of the resolution and for consideration of war.

On Monday, White House national security adviser Condoleezza Rice traveled to New York to discuss Blix's weekend visit to Baghdad, inquire about the tenor of his upcoming presentation and press for tough findings. Yesterday, Blix was also visited by Iraqi, French, Belgian and Australian officials.

France has circulated a document calling for greatly increasing the more than 100 inspectors now operating in Iraq, as well as giving them additional capability to examine documents and guard potential weapons sites. The United States has dismissed this proposal, and Blix has already said that full Iraqi cooperation was much more important than additional inspectors.

The United States and its closest council ally, Britain, have drafted a number of resolutions to demand a council decision. But diplomatic sources said yesterday that they will not introduce a resolution before next week at the earliest, unless France does.

Meanwhile, the council has scheduled an additional session for Feb. 18, at the request of nonmember countries that have asked to be heard on Iraq. In an earlier presentation, South Africa, the head of the nonaligned movement, said that those countries are opposed to war and favor ongoing inspections.

Staff writer Colum Lynch at the United Nations contributed to this report.

Greeting Lombardy's President Roberto Formigoni in Rome yesterday, Iraqi Deputy Prime Minister Tariq Aziz, left, says Iraq is "no threat to anyone."