Gen. H. Norman Schwarzkopf said Wednesday that two weeks of bombing raids have forced Iraq to abandon centralized control of its air defense. He said the allies have supremacy in Iraqi skies.

"As you know, we've flown more than 30,000 sorties and we've lost only 19 aircraft," the U.S. commander of Operation Desert Storm told reporters."The F-117 remains virtually invisible and highly effective," he said of the American Stealth warplane. "As a result, the Iraqis have abandoned centralized control of their air defense within Iraq and Kuwait."

Schwarzkopf said the bombing was aimed at the "systematic destruction" of the Iraqi air force's hardened shelters and that more than 70 have been destroyed.

"The Iraqi air force is running out of places to hide," he said.

"The simple fact is: Now, every time an Iraqi airplane takes off the ground, it is running away."

During his briefing, Schwarzkopf used maps and video segments to illustrate the allies' progress in the war to liberate Kuwait.

He said allied forces had destroyed all of Iraq's nuclear reactors, half of its biological warfare plants, and chemical storage and production sites.

One Baghdad nuclear center has been reduced to rubble, he said.

"We're going to continue a relentless attack on this very, very heinous weapons system," he said.

He said attacks on an ammunition dump in northern Kuwait caused a tremendous explosion, more powerful than a blast of a volcano.

Asked how he felt about Iraq's use of prisoners

of war as human shields, Schwarzkopf said it was a violation of the Geneva Convention, and that the Red Cross had access to allied camps for captured Iraqis.

Raising his voice, he said, "I challenge, I challenge the Iraqis right now to do the same damn thing in their POW camps."

The number of allied forces has passed half a million, the highest level yet, he said.

"By declaring air supremacy, it gives us the ability to use some new tactics we have not been able to use before," he said.

Schwarzkopf said 46 Iraqi naval vessles have been sunk or disabled.

Asked about stopping the gigantic oil spill in the Persian Gulf, he said, "The U.S. Navy is very proud of any role we may have played in doing away with this act of ecological terrorism."

He also said allied forces apparently were able to prevent an Iraqi Scud missile attack on Israel on Tuesday night.

"I have a high degree of confidence we're getting better and better at our ability to find them," he said of the Scuds.

He said the ammunition depot that was destroyed had supplied all Iraqi forces in Kuwait.

"What they've got is what they've got, and if they use that up they're going to be hurting," Schwarzkopf said.

With air superiority, he said, the allies would now attack supply convoys for forces in Kuwait.

"By every measure, our campaign plan is very much on schedule. There's no way I'm suggesting that the Iraqi army is about to give up, but I am quite confident that . . . is going to lead to the outcome we all want to see."

- Meanwhile in Washington, President Bush Wednesday invoked the memory of another wartime president, Franklin Roosevelt, to rally support for Operation Desert Storm, and said the goal of the war is the triumph of a new "moral order" in the world.

"We ask God to bless us, to guide us and to help us through whatever dark nights we still may face," the president said in remarks to lawmakers in the Capitol.

Bush noted that 50 years ago, with the United States on the verge of World War II, Roosevelt articulated four freedoms - freedom of expression, freedom of worship, freedom from want and freedom from fear.

"No one knew better than President Roosevelt what hard work freedom really is," he said.

He quoted Roosevelt as saying, "The justice of morality must and will win in the end."

Bush said a 28-nation coalition is "standing up to the evil" in the Persian Gulf region.

"The triumph of the moral order must still be the vision that compels us," he said.

- In London, military sources said Wednesday that a new oil slick has appeared in the Persian Gulf, emanating from an Iraqi oil terminal.

"We are aware of an extra slick," said a British official, speaking on condition of anonymity.

He confirmed an earlier report from the British Broadcasting Corp. that the slick had been detected within the previous 24 hours.

BBC Radio diplomatic correspondent Paul Reynolds said the source of the slick is Mina al-Bakr, a large offshore Iraqi terminal northeast of the Kuwaiti island of Bubiyan.

"According to officials, Iraq for the last 24 hours or so has been deliberately pumping oil into the sea in the same way that it did before," Rey-nolds said.

"The way they put it here is `a significant number of thousands of barrels' - they don't have a precise figure, but they are absolutely certain that it is not the result of bombing," Reynolds said.