The United Nations chief weapons inspector, Hans Blix, will tell the UN Security Council today that key questions remain unanswered about Iraq's possible possession of prohibited weapons of mass destruction and that his meetings last week in Baghdad "gave no signs of major movement" toward full disclosure, according to senior UN officials.

In what he has insisted will be only an 'update' on the weapons inspections programme that began in November, Blix plans to note both the negative and the positive aspects of Iraqi cooperation during the first 60 days of inspections, the officials said.

Blix had been prepared to be more positive in his presentation before his meetings in Baghdad last Sunday and Monday, the senior officials said.

But Iraqi officials showed little interest in moving away from their position that they have no chemical, biological or nuclear weapons to declare and no more documents to produce.

As a result, Blix expects to tell the Security Council that Baghdad has not been 'proactive' in assisting the inspectors' access to information, the officials said.

Blix's presentation will mark an important milestone in the Bush administration's confrontation with Iraqi President Saddam Hussain over his banned weapons programmes.

Administration officials have pointed to the report as the beginning of a new phase in the crisis they hope would lead to greater support within the Security Council for its contention that Iraq has violated its international obligations and that the use of force is warranted.

But the report will likely fall short of the administration's desire for a harsh assessment that would demonstrate Iraq has consistently violated its disarmament obligations.

Painted more in shades of gray than in black and white, the report could provide more ammunition to those countries on the Security Council that want the inspections to continue and that oppose an immediate decision to go to war.

U.S. and diplomatic sources said last week that, in the face of stiff opposition by leading council members, the administration will agree to support more weapons inspections, at least for several more weeks. Talks among council members would continue during this period, with another Blix update due in mid-February.

The extended time frame would also suit the Pentagon's deployment schedule for U.S. military forces under which all the major components of a ground invasion would not be in place until late February at the earliest.

Blix has not discussed how long he believes inspections should run, since he considers that the responsibility of the Security Council.

"If we have the proactive cooperation (of Iraq), if they really make an effort in all respects, then we should not need very much time," the Swedish diplomat said last week. His current plan is to present regular updates and another major report March 27.

In public and private statements last week, U.S. officials urged Blix to report that Iraq has violated its disarmament obligations by barring surveillance flights, interfering with UN interviews of Iraqi scientists and developing missiles with a range greater than the 90-mile limit allowed under UN rules, according to U.S. and UN officials.

The U.S. effort was designed to persuade Blix to formally place as many specific Iraqi violations as possible on the record before the Security Council.

Blix's specific criticisms of Iraq - based on the first 60 days of inspections - will in some parts follow along the lines U.S. officials have discussed.

But the senior UN officials said Blix does not plan to pass judgment on some of the issues raised by the United States, instead referring to them as gaps in the inspections effort that are still open to question. They added that his report will contain some praise for the Iraqis.

Senior UN officials said that while they are prepared to fully exercise authority to inspect any Iraqi home, they are willing to wait for a reasonable period to allow the head of the household to return home.

"This is a conflict between the most rigid and legalistic approach," said a senior UN official. "We need to strike the right equilibrium.

If waiting half an hour - knowing that nothing is happening, no destruction of evidence - allows us to behave like human beings, then we will do it."

In his report today, Blix might raise a new concern - that intelligence passed to his inspectors on sites to be visited might have leaked to the Iraqis. At one recent inspection site, Iraqis moved materials before the UN group arrived, one UN official said Saturday.

Blix will cite the Iraqi government's failure to encourage Iraqi scientists and technicians to agree to private interviews despite promises that Iraqi Gen. Hossam Amin, director of the Iraqi National Monitoring Directorate, delivered in the joint statement last week with Blix and Mohammed El Baradei, the director general of the International Atomic Energy Agency, the officials said.

Blix will also describe Iraq's refusal to permit the inspectors' use of U.S.-piloted U-2 surveillance aircraft without conditions, which he described as "unacceptable."

Blix will note that, despite his warnings, Iraq has yet to answer key questions left by gaps in Baghdad's December 7 declaration of its chemical, biological and nuclear weapons programmes, which was supposed to have been "full, final and complete."

He will report that Iraq has yet to answer his commission's questions about certain of its more recent purchases of materials that could be used in the manufacture of banned weapons.

For example, he will discuss questions given Iraq about the purpose of nearly 100 newly-bought missile engines as well as what type of warheads they were supposed to carry.

He has not gotten answers to questions about Iraqi purchases of missile fuel and a type of chemical explosive usable in some weapons. Blix has about 100 outstanding issues with Iraq in 30 categories.

© Los Angeles Times-Washington Post News Service