Administration officials yesterday played down the launch of U.S. Navy planes from an aircraft carrier near the Persian Gulf last weekend at a time when the United States is closely monitoring activity at Iranian Silkworm antiship missile sites.

Pentagon officials said the airplanes were launched as a drill in preparation for U.S. military escort of Kuwaiti tankers flying the U.S. flag in the gulf. White House officials said the jets were sent aloft in connection with the USS Stark's departure from Bahrain en route to its home port in Florida.

Other Pentagon officials told The Washington Post Sunday that the launching of the planes, including bombers, was triggered by suspicious activity at a Silkworm base late last week. One official said that some Pentagon officials believe Adm. William J. Crowe Jr., chairman of the Joint Chiefs of Staff, may have overreacted to fragmentary intelligence information when he ordered the planes launched. The official said the launching was a precautionary measure and did not represent a decision to take out the Silkworm missiles in a preemptive strike.

The launching of the planes "had nothing to do with the Silkworms," White House spokesman Marlin Fitzwater said yesterday. "It was not meant to be provocative in any way. It did not infringe on Iran airspace and was in no way related to the Silkworms."

Pentagon officials said yesterday that intelligence reports showed that one Silkworm site at the Strait of Hormuz was being readied for a possible test missile last week. Officials said that Iranians, at the end of last week, "dismantled all of the stuff at the site," demonstrating that they could prepare a missile for deployment in a short time.

The officials said the operation from the carrier in the nearby Arabian Sea was unrelated to the activity at the missile site. Officials said the Joint Chiefs of Staff last Thursday discussed a training exercise with the Middle East Task Force and Pacific Fleet ships outside the gulf in preparation for escorting reflagged Kuwaiti ships beginning in mid-month.

Final approval for the exercise was granted Saturday, according to the Pentagon chronology. Officials said the airplanes participated in a joint exercise with surface ships for several hours.

Pentagon officials said the exercise was planned in conjunction with a major movement of U.S. military ships in and out of the Persian Gulf through the Strait of Hormuz, considered the most potentially dangerous path the reflagged Kuwaiti ships will take. The USS Stark, partially repaired after the attack by Iraqi-fired Exocet missiles May 17 that left 37 sailors dead, was moving through the strait en route to its home port at Mayport, Fla. Several other ships accompanied the Stark.

At the same time, several ships that will be serving as escorts for the Kuwaiti tankers were sailing into the gulf.

Pentagon officials said the ship activity provided an opportunity for the planes and ships to practice communications and potential reaction to attacks from Silkworms, surface or air missiles.

The Chinese-made Silkworm missile has a range of about 60 miles and carries a 1,000-pound warhead.

Pentagon officials said the United States will provide air cover and ships will operate at full battle stations while escorting Kuwaiti ships through the strait.