Top U.N. arms inspectors met with Iraqi officials Saturday to determine what Baghdad did with stores of anthrax, nerve gas and other forbidden arms.

After more than four hours of meetings, U.N. nuclear watchdog Mohamed ElBaradei reported the Iraqis had supplied "explanations on some of the issues." Chief arms inspector Hans Blix called the talks "useful" and "substantial."

The talks were crucial, but they were "not the last chance" for peace, ElBaradei said, apparently responding to talk in Washington that the time for diplomacy had all but run out. Discussions will resume Sunday.

ElBaradei and Blix were hoping to convince Iraq to make concessions on practical matters in the disarmament effort, such as clearance to fly American U-2 reconnaissance planes in support of the probe.

They were also looking to secure continued interviews with weapons scientists in private. Another scientist attended a private meeting Saturday -- the fifth in three days.

In addition, U.N. inspectors wanted Iraq to provide documents, testimony or other evidence to explain discrepancies in Iraq's accounting for weapons of mass destruction produced and weapons destroyed over a decade ago.

"If they don't have the orders (to destroy weapons), if they don't have the paper, give us the people who were involved, to talk to," one U.N. delegate said before the first meeting, in a Foreign Ministry conference room above a boulevard lined with statues that glorified President Saddam Hussein.

The first round of talks opened just after 4 p.m. Saturday with an hour of high-level talks between Blix, ElBaradei and Lt. Gen. Amer al-Saadi, a Saddam Hussein adviser and head of the Iraqi delegation. That was followed by more than three hours of a full meeting between delegations.

Afterward, Blix told reporters, "It is useful discussions we are having. ... It was a very substantial discussion." But neither he nor ElBaradei were specific about the "explanations" offered by their Iraqi counterparts.

Another senior U.N. official, speaking on condition of anonymity, said the Iraqis had presented documents but they would have to be studied before inspectors could determine their value. He did not divulge the amount of documents handed over or specify their subject matter. No Iraqi officials spoke with reporters afterward.

The two days of Baghdad talks will greatly influence the reports the chief inspectors must present next Friday to the U.N. Security Council, whose member nations hope to unanimously decide on the next step in the crisis.

The council majority is pulling for something short of a U.N. authorization for military action against Iraq, sought by President Bush and British Prime Minister Tony Blair.

The U.S. and British governments argue that Iraq still operates chemical, biological and nuclear arms programs prohibited by U.N. resolutions, and threaten a military strike if not satisfied Saddam has disarmed.

In a jab at major U.S. allies, Defense Secretary Donald H. Rumsfeld said Saturday countries such as France and Germany that favor giving Iraq more time to disarm are undermining what slim chance may exist to avoid war.

"There are those who counsel that we should delay preparations" for war against Iraq. "Ironically, that approach could well make war more likely, not less, because delaying preparations sends a signal of uncertainty," Rumsfeld said in the opening address at an international conference on security policy.

German Foreign Minister Joschka Fischer, at the same Munich conference, spoke against accepting "the logic of a military campaign."

"We must give the inspectors more time," he said.

Bush said he will not wait much longer before moving against Saddam Hussein, declaring in his weekly radio address that the Iraqi leader is wasting a last opportunity to come clean.

In Berlin, meanwhile, a weekly magazine reported Germany and France were working on a broad disarmament plan for Iraq designed to avoid war, including the deployment of U.N. soldiers throughout the country, reconnaissance flights and increasing the number of weapons inspectors to 300.

The plan could be presented to the U.N. Security Council as a resolution, Der Spiegel said, though it was unclear how the two countries or the United Nations would win Saddam's approval for carrying it out.

Rumsfeld, who heard about the proposal through the press, asked about it while meeting with German Defense Minister Peter Struck. But Struck refused to discuss the proposal, saying, "I am not ready to talk about it yet," according to reports.

That response angered the defense secretary, who was concerned the proposal would seriously hinder momentum leading to possible military action, according to a Pentagon official.

American military units, meanwhile, continue to converge on the Persian Gulf region, more than 100,000 personnel thus far to back up the U.S. threat.

Fox News has confirmed that a number of F-117 fighter jets are now based at Al-Udeid Air Base in Qatar. The planes arrived Thursday, joining the F-15 and F-16 fighters that have been stationed there for about two weeks.

In Turkey, top civilian and military leaders agreed to let the United States send 38,000 troops to the country to open a northern front in any Iraq war, private television NTV reported.

Washington had asked to station 80,000 troops in Turkey, but in the face of strong public opposition to war Turkish leaders asked that the United States reduce the figure.

In the central Iraqi city of Tikrit, Saddam's hometown, thousands of soldiers and civilian militia members -- women and older men among them -- marched in a display of readiness for any U.S. attack, holding Kalashnikov assault rifles aloft, carrying outsized portraits of Saddam.

Against this talk of war and peace, the more than 100 U.N. inspectors went about their daily business in Iraq. Inspectors paid surprise visits to industrial sites and a technical institute, and a nuclear team surveyed parts of Baghdad with a vehicle monitoring for radiation.

The Iraqi Foreign Ministry said that one U.N. team cordoned off an area in Baghdad for four hours on Saturday and searched a printing plant, a military factory and a kindergarten. Saturday was a holiday in Iraq and no classes were in session.

U.N. officials were not immediately available for comment.

The Security Council banned Iraqi weapons of mass destruction and longer-range missiles after Iraq's defeat in the 1991 Gulf War. During the 1990s, U.N. inspectors oversaw destruction of the great bulk of chemical and biological weapons, and dismantled Iraq's program to build nuclear bombs.

The U.N. experts resumed inspections last Nov. 27, after a four-year gap, to certify that Iraq has no leftover weapons and did not restart the arms programs during the U.N. absence.

In a Security Council report Jan. 27, after two days of talks here, Blix declared the Iraqis were cooperating on inspection procedures, but not on "substance" -- meaning by supplying evidence to clear up lingering questions about VX nerve agent, anthrax and some other doomsday weapons developed in the 1980s.

Iraq has not documented all its reported destruction of VX, for example. International experts found traces indicating VX neutralization at a designated location, but could not certify the amount. In the same way, gaps exist in records of Iraq's declared unilateral destruction of the biological agent anthrax.

Returning to Baghdad this time, the chief inspectors were looking in particular for documents, witnesses or forensic evidence to close such gaps.

The Associated Press contributed to this report.