DUBAI, UNITED ARAB EMIRATES, FEB. 22 -- The U.S. Navy, which now considers errant Iraqi warplanes as the most pressing threat to American forces in the Persian Gulf, was expected to remind Baghdad in talks opening there today that U.S. warship commanders have the authority to shoot down Iraqi aircraft approaching U.S. vessels.

A four-man Navy team led by the chief of staff of the U.S. Middle East Force based in the gulf met with Iraqi military officials amid what U.S. officials described as growing frustration that Iraqi pilots have failed to adhere to rules laid down after last May's Iraqi missile attack on the USS Stark, which killed 37 American sailors.

The Navy delegation was dispatched after an Iraqi long-range Tu16 bomber fired two powerful antiship missiles near a convoy of U.S. warships and reflagged Kuwaiti tankers on the night of Feb. 12.

Under rules worked out between Washington and Baghdad last spring, U.S.-manned airborne warning and control system (AWACS) surveillance planes on continuous patrol over the gulf hail all Iraqi warplanes whose course would take them near U.S. vessels.

"Once the Iraqis come within a certain distance, the AWACS will tell them to break away," one U.S. military official said. If the Iraqi pilots continue on their course, the U.S. warship commanders pick them up, issue separate radio warnings and may fire flares to ward off the plane before deciding to fire antiaircraft guns or missiles.

U.S. officials said Iraqi pilots have frequently violated these rules. In an incident Thanksgiving Day, the captain of the USS Richmond K. Turner came within seconds of shooting down two Iraqi warplanes bearing down on his ship, according to military sources. The Iraqi pilots failed to heed warnings from AWACS to alter course.

"We treat Iraqi planes now as more of a threat than Iranian planes," said a U.S. military official. "The attitude is that if something is not done, it is going to happen again," the official added, referring to the Stark incident. If it does, U.S. commanders are "very, very concerned," he said, that what the United States sees as its largely successful mission in the Persian Gulf will be thrown into crisis.

"The public outcry is going to be unbearable," the official said, and U.S. relations with Iraq, already strained by the Stark incident, will be seriously damaged. Arab leaders who have sought U.S. assistance to protect international sea lanes and prevent a spillover of the Iran-Iraq war fear such an incident would lead to the collapse of U.S. resolve to maintain its presence here.

Gen. George B. Crist, commander of the U.S. Central Command, which has overall responsibility for Persian Gulf forces, sent a strong message to Baghdad the night of Feb. 12 incident, according to sources, and was said to be "very upset" by indiscriminate Iraqi targeting procedures.

"He told them to knock off" that activity, according to a military official familiar with the tense sequence of events as one of the Iraqi missiles -- described by the Navy as a Chinese-made air-launched version of the Silkworm -- blazed across the night sky to within eight miles of the USS Chandler and USS Reuben James and four tankers.

Iraq, which supports the U.S. deployment here and receives satellite intelligence from the United States relating to Iranian moves in the seven-year-old land war, has suspended its air strikes on shipping targets in the gulf.

One U.S. official in the region said the purpose of the U.S. delegation's visit to Baghdad was to restate the U.S. warning procedures, and also "to give them hell" for plaguing the U.S. fleet with frequent calls to general quarters.

The USS Chandler fired warning flares at the Iraqi bomber on Feb. 12 moments before the plane turned and fired its two missiles at no apparent target. The Chandler's captain criticized Iraq's targeting tactics over the busy gulf shipping lanes.

"The Iranians seem to exert a lot of care as to what ship they're going to hit, and the Iraqis don't," Cmdr. Steve Smith told Pentagon pool reporters after the incident. "The Iraqis come down and they shoot at radar blips."

After the Turner and Chandler incidents, senior Navy officials here made it clear to all U.S. warship commanders in the area that in both cases, the ship captains would have been "perfectly within their rights" to shoot down the Iraqi planes, one military source said.

This reiteration of command support among U.S. gulf forces was seen by some western officials here as an effort by the U.S. command to avoid another Stark incident by removing all cause for doubt or second thoughts by warship captains apprehensive about shooting at "friendly" Iraqi aircraft that were flying missions against Iranian shipping lanes.

U.S. military sources and shipping officials in the gulf said in interviews last weekend that Iraq also fired an air-launched missile at a Danish supertanker on Feb. 11. The supertanker had no connection with Iran and was on its way out of the gulf with Saudi crude oil for customers in the United States.

The missile hit the superstructure of the 339,000-ton Kate Maersk, killing a radio operator and seriously wounding three crewmen.

A U.S. military official said Navy warships monitored an Iraqi Tu16 bomber as it approached the Kate Maersk and crewmen in a U.S. convoy 15 miles away saw the Iraqi missile flash across the horizon and explode.

The strike on the Kate Maersk originally was reported by news agencies as an Iranian attack, but U.S. officials said there were no Iranian gunboats or aircraft in the area when the attack occurred. In addition, Iraq's state news agency claimed that its Air Force struck a "very large naval target" that night.

U.S. military officials also are concerned that Iraq's use of the long-range TU16s equipped with air-launched versions of the Silkworm -- which is used by Iran -- presents a new threat to U.S. and other neutral shipping.

"The Iraqis are changing tactics," said a shipping executive. "They are trying to extend their range farther down into the gulf," where Iranian shipping lanes and heavy commercial traffic bound to and from Arab ports come within a few dozen miles of each other.

Military and shipping officials said they could not recall any previous use by Iraq of the Silkworm antiship missile, which is an adaptation of the Soviet-designed Styx. They said they did not know where Iraq had gotten the missiles.