DUBAI, UNITED ARAB EMIRATES, AUG. 24 -- U.S. warships fired warning shots at fishing vessels and chased away an Iranian naval ship today during a tense completion of a journey through the Persian Gulf for a convoy of reflagged Kuwaiti tankers.

The guided-missile destroyer USS Kidd fired machinegun bursts across the bows of two small dhows this morning when the traditional sailing vessels of the gulf approached the convoy of tankers as it neared the Strait of Hormuz, the Pentagon reported.

The dhows, small wooden craft used for fishing and transporting freight, normally do not carry radios and did not respond to warning flares from the Kidd, prompting the shots. They were the first shots fired at other vessels by U.S. Navy ships since they began their convoy duty in the gulf on July 22, according to a Pentagon spokesman. He said the dhows were of "unknown nationality."

Two weeks ago a Navy Tomcat F14 jet fighter fired two Sparrow missiles at what was believed to have been an Iranian fighter that came too close to U.S. aircraft accompanying a convoy. Both the missiles missed their target. Pentagon officials have never publicly confirmed the incident.

{In Washington, Pentagon officials said a support helicopter based on the destroyer USS Kidd first spotted the two dhows about eight miles from the Kidd. A statement said the Kidd had to fire twice before the dhows turned away.}

Later this afternoon, as the tankers neared the end of their journey, a small Iranian warship approached the convoy, prompting a 10-minute test of wills that is characteristic of scores of daily challenges by Navy vessels to unknown boats and planes.

The Iranian vessel was challenged to identify itself and then was warned to stay away from the convoy, according to reports from persons monitoring open marine emergency channels.

"U.S. war ship, I am proper, I am doing my daily routine in international waters. Over," the Iranian vessel replied.

Footage of the incident taken by West German television shows the amphibious assault ship USS Guadalcanal and a frigate positioning themselves near the Iranian ship and helicopters from the Guadalcanal approaching it.

In the background, a heckler can be heard on the open marine channel saying, "American warship, shut up. American warship, shut up."

"We had just finished the convoy operation and cleared the area," Capt. Skip Dirren, skipper of the Guadalcanal, told the media pool accompanying the convoy. "We were turning southbound to return to another operational area. {The frigate USS} Jarrett was instructed to position herself tactically between the convoy and the Iranian vessel, which is the normal procedure in tactical formation."

Dirren said he could not determine what were the intentions of the Iranian ship. "My guess is that she was just observing what was going on," he said.

An Associated Press reporter covering the escort operation in a news pool from a helicopter said the Iranian ship, a British-built amphibious landing ship, appeared to be less than 500 yards from the Jarrett.

After about 10 minutes, the Iranian ship gave up and moved away from the convoy, which proceeded through the Strait of Hormuz and into the Gulf of Oman.

A 2 1/2-hour helicopter ride over the greenish gray waters of the gulf this afternoon demonstrated the care with which U.S. Navy vessels, and British warships in the gulf, are watching anything that approaches.

Well before a ship could be seen through the haze covering the gulf waters, the radio aboard the helicopter crackled with a distinctly American accented voice saying, "Unidentified helicopter . . . , this is a U.S. Navy warship in international waters. Please identify yourself, and please state your intentions."

The helicopter pilot responded with his call letters, said he was carrying journalists, including a television crew, and sought permission to approach for filming.

The Navy ship, which did not identify itself further, answered politely but firmly ordering the helicopter to stay at least 4,000 yards away.

The same sequence repeated itself with a British warship accompanying a tanker in the gulf.

News agencies quoted shipping sources late in the day as saying another U.S.-escorted convoy of reflagged tankers had begun its journey to Kuwait, but there was no independent confirmation.

{In Washington, the State Department said Britain will reflag a Kuwaiti oil tanker, entitling it to Royal Navy protection in the gulf. A State Department statement noted that "reflagging to the British is considered merely an administrative matter and is not subject to the approval of the British government if certain statutory conditions are met."}

Washington Post special correspondent Michael J. Berlin reported from the United Nations:

After meeting Monday with U.N. officials and several Security Council delegates, the Iranian deputy foreign minister expressed Iran's willingness to renegotiate the terms of a July 20 council resolution that calls for a cease-fire in the nearly eight-year-old Persian Gulf war.

Although he made clear that the resolution's cease-fire demand remained unacceptable to Iran, Mohammed Jawad Larijani said, "We hope something positive can be cooked out of this resolution."

{In Tunis, Arab League foreign ministers formulated a draft resolution urging Arab states to break relations with Iran until it accepts the U.N. resolution, Reuter reported. The draft will be submitted to a plenary session of the Arab League's council of ministers Tuesday.}

Some western diplomats, including Iraqi U.N. representative Ismet Kittani, cautioned that Iran's objective appeared to be to drag out discussions and delay consideration of a second U.N. resolution that would impose an arms embargo on Iran for failing to comply with the cease-fire. Iraq has agreed to the U.N. cease-fire terms. Staff writer Molly Moore contributed to this report.