The United States appears to be providing U.N. weapons inspectors in Iraq with a reasonable amount of information about where they can find weapons of mass destruction, two key lawmakers say.

Sen. Pat Roberts, the likely chairman of the Senate Intelligence Committee, and Rep. Jane Harman, the House Intelligence Committee's top Democrat, said U.S. officials are trying to help inspectors while not revealing intelligence sources and methods.

"It's a careful balance," Harman, D-Calif., said in an interview Thursday. "My strong impression that we are all working well together."

Roberts, R-Kan., said in a separate interview that the cooperation has been "reasonable under the circumstances."

"I think there has to be confidence gained on both sides," he said.

International Atomic Energy Agency head Mohamed ElBaradei, after a meeting Friday with Senate Foreign Relations Committee Chairman Dick Lugar, R-Ind., said he was satisfied with the intelligence his agency is receiving from the United States, but hopes to receive more.

"We are getting intelligence," ElBaradei said, but "we need more actionable information ... we need specific information on where to go and where to inspect."

Meanwhile, the Pentagon said that U.S. warplanes struck five air defense sites in southern Iraq Friday as preparations continued for a possible war to oust Saddam Hussein.

The fighters used precision-guided weapons to attack an air defense command and control site at Tallil, about 170 miles southeast of Baghdad, said a statement from U.S. Central Command said. And officials at Camp Lejeune, N.C., said some 7,000 Marines from that base will be sent to join U.S. forces in the Persian Gulf.

White House spokesman Ari Fleischer said Friday that Bush would meet later in the day with representatives of Iraqi opposition groups. "The president wants to talk to them about his hopes and dreams for the future of a free Iraq that is inclusive and unified and democratic," Fleischer said.

Asked about odds of war being averted, Fleischer told reporters: "I've not heard the president put odds on it. ... This is something that Saddam Hussein will ultimately decide."

The United States says Iraq has developed chemical and biological weapons and could develop nuclear weapons. Chief weapons inspector Hans Blix has called on the United States to share intelligence to help inspectors find the weapons. Secretary of State Colin Powell said in a Washington Post interview published Thursday that significant information has been given to the inspectors, to allow them to work more aggressively.

Blix told the U.N. Security Council on Thursday that no "smoking guns" had been found. Blix, however, also said Iraq's claim it has no weapons of mass destruction in violation of a U.N. resolution is impossible to verify because its declaration left out so much information.

Roberts said information provided by the United States would likely lead to piecemeal evidence of Iraq's weapons programs.

"I doubt seriously under the circumstances you're going to find a specific instance or piece of information that represents what everyone calls a smoking gun -- a just unequivocal piece of information," he said.

At the White House, the administration cast Blix's comments as supporting the U.S. position that Iraq has so far failed to prove it does not possess banned weapons.

Fleischer cited portions of the inspectors' briefing that chided Iraq for not presenting evidence to prove it does not have weapons of mass destruction, and for failing to resolve questions about missile engine imports, the chemical agent VX and the full list of scientists who worked on weapons programs.

"The problem with guns that are hidden is you can't see their smoke," Fleischer said. "We know for a fact that there are weapons there."

Blix and the IAEA's ElBaradei said the inspections process needs more time. ElBaradei is also meeting Friday with Secretary of State Colin Powell and Condoleezza Rice, President Bush's assistant for national security.

A formal report from the inspectors is due Jan. 27. U.S. officials had indicated Bush would decide shortly thereafter whether to order an invasion of Iraq.

Fleischer called the deadline merely "an important reporting date."

On one specific weapons matter, ElBaradei said aluminum tubes obtained by Iraq were not suitable for enriching uranium for use in a nuclear weapon. But Fleischer said the acquisitions, banned under U.N. resolution regardless of their purpose, remain a cause for concern.

"They are pursuing acquisition of elements that are banned to them that have purposes, that still can be used for military purposes," he said. "We do have concerns about their potential of developing nuclear programs."

Fleischer also suggested that the United States' military buildup could be useful as a tactic to prod the Iraqi leader to comply with U.N. requirements.