As he prepared his report for a critical U.N. Security Council meeting, the top U.N. nuclear weapons inspector said Thursday that inspections should continue for months because "we are moving forward."

Despite increasing U.S. pressure to move militarily against Baghdad, Mohamed ElBaradei said war is not a foregone conclusion, provided "we see some progress on the part of Iraq" in revealing any hidden weapons of mass destruction.

"We're still in midcourse, but we are moving forward, and I see no reason for us to bring the inspection process to a halt," ElBaradei told The Associated Press as he drafted his report on a flight from Vienna, Austria, to New York.

ElBaradei, director-general of the U.N. Atomic Energy Agency, is to deliver his progress report Friday on the 2-month search for evidence of Iraqi nuclear weapons programs. Also reporting to the council will be Hans Blix, who heads the hunt for Baghdad's biological and chemical weapons.

ElBaradei refused to go into detail on his report.

But he suggested that he would ask for more time, reiterating that his inspectors need months to finish their job -- a view opposed by the Bush administration, which is pressing ahead with plans to invade Iraq with or without U.N. blessing.

ElBaradei also said the questions that still remain about Iraq's nuclear program include reported imports of uranium, smuggled aluminum tubing, and other components that could be used in a weapons program.

Concerns identified by ElBaradei included "the questions of aluminum tubes,the question of importation of magnets, and the question of importation of carbon fiber" as well as reported imports of uranium.

The magnets and carbon fiber as well as the aluminum tubing could potentially be used in centrifuges to make fuel for nuclear warheads, according to experts at the Vienna-based agency.

"These are the kinds of issues we are looking at," he said. Agency officials who spoke on condition of anonymity said ElBaradei would raise these concerns at the council meeting.

He suggested his report will not give a definite use for aluminum tubing because "we are still conducting investigations" based on additional information from the Iraqis.

On another subject, ElBaradei said American U-2 planes "should be flying this week." Iraq recently accepted reconnaissance flights by American U-2 aircraft.

Earlier Thursday, Gen. Hossam Mohamed Amin, chief Iraqi liaison to the U.N. inspectors, confirmed that Iraq had set restrictions on the use of surveillance aircraft.

He said a letter had been sent to Blix, insisting on "all information about when these planes are entering Iraqi airspace, the altitude and speed of the plane, I mean the surveillance plane. We also need the call sign, and the time and date they enter Iraqi airspace. If we get this information we can guarantee the safety of the pilot and the plane."

ElBaradei said he supported increasing the number of inspectors -- a move favored by Germany and France, which oppose U.S. calls for military action and favor giving the U.N. weapons search more time.

"We need a strong, intrusive regime," he said, in making the case for expanding inspectors past their present strength of 119 -- most of them involved in the biological and chemical weapons search.

"We would like to see our inspections beefed up, but that's no substitute for full and active Iraqi cooperation."

ElBaradei said there are no plans to send U.N. peacekeepers to augment the inspection teams but added he would welcome additional "security personnel" to work hand-in-hand with the inspectors.

Such extra security would "protect our sites from infiltration but not ... in any way enforce inspections," he said. "To enforce inspections is really the duty of the Security Council."