The U.S. military command in Saudi Arabia said Wednesday that Iraq is showing no sign it is preparing to pull out of Kuwait, and the Americans suggested there are weaknesses in Iraqi air and naval defenses.

The officials, briefing reporters in the Saudi capital, also reported that a Navy ship had run aground in the Arabian Sea and caused an oil slick, and that U.S. forces in the Persian Gulf region have increased to 325,000.The comments came at the second of what the military says will be regular weekly briefings on Operation Desert Shield, the U.S. deployment launched in the gulf region after Iraq's Aug. 2 invasion of Kuwait.

"We see no evidence that Iraq is withdrawing from Kuwait," said one of the briefers, Army Lt. Col. Greg Pepin.

Iraq now has 510,000 troops in southern Iraq and Kuwait, Pepin said. Its forces include 4,000 tanks, 2,500 armored personnel carriers and 2,700 artillery pieces in the Kuwaiti theater.

The U.S. forces in the region include about 195,000 Army troops, 55,000 Marines, 35,000 in the Navy and 45,000 Air Force personnel, Pepin said. The U.S. contingent now has more than 1,000 main battle tanks and 2,000 armored personnel carriers, he said.

The officials refused to discuss the question of U.S. readiness for combat after Jan. 15, the deadline set by the United Nations for Iraq to withdraw or face possible military force.

"That question's been discussed at a level far above mine and I really have nothing to add to it," Pepin said.

He also declined to say whether it would be possible for Iraq to get its forces out of Kuwait in time to meet the deadline. "I have no way of assessing how they could pull out," he said.

Pepin said the United States now has 55 ships and more than 1,300 aircraft in the gulf region, up from more than 1,000 last week.

Discussing Iraqi air readiness, Pepin said there recently had been more air activity by the Iraqis. But he added that "Iraqi pilots have not demonstrated sufficient siutational awareness or training to successfully respond to a fast-paced, dynamic" military engagement.

Pepin also said the Iraqi navy had been holding "low-key" operations in recent days.

"Iraq may be attempting to preserve its relatively small fleet for possible conflict," he said.

The grounded U.S. ship was identified as the oiler Andrew J. Higgins, which ran aground on an uncharted reef in the northern Arabian Sea, spilling about 2,000 gallons of a mixture of fuels.

Pepin said the spill had caused a 300-yard slick near the ship and that an investigation was under way.

The Higgins is a San Francisco-based oiler, a refueling ship, with a civilian crew of 98 and a Naval communications detachment of 21.