The Navy has ordered its warships to fully man battle stations while traveling though the Strait of Hormuz at the mouth of the Persian Gulf and will position an aircraft carrier year round in the Indian Ocean to help protect Kuwaiti tankers in the gulf, according to a Defense Department report sent to Congress yesterday.

The report, detailing Pentagon security plans for escorting 11 Kuwaiti oil tankers flying U.S. flags in the gulf, said current "rules of engagement" spelling out the defense of U.S. ships facing hostile threats are not expected to change when the escorts begin in the next few weeks.

Although the 26-page, unclassified version of the report to Congress included only sketchy details of the Pentagon's plans, sources said preliminary proposals provide for escorting the reflagged Kuwaiti ships in daylight to reduce the chances of misidentification by Iraqi and Iranian warplanes and warships. While traversing the gulf, where more than 200 commercial ships have been attacked in the past several years as a consequence of the Iran-Iraq war, each Kuwaiti tanker would be escorted by at least two U.S. warships, according to Pentagon sources.

In addition, U.S. officials are negotiating with Saudi Arabia for further Saudi fighter protection for U.S. Airborne Warning and Control System (AWACS) planes flying over the southern gulf; Washington also is seeking permission from Oman for U.S. flights through that country's airspace, administration sources said.

"The plan is not risk-free," the report from Defense Secretary Caspar W. Weinberger stated. "Threats to American warships and protected U.S. vessels do exist." However, the report rated the risks as "low to moderate."

Some members of Congress and Pentagon officials have expressed concern that plans to escort Kuwaiti tankers could make U.S. warships potential targets because Kuwait is an ally of Iraq in the gulf war.

The report cautioned that Iranian deployment of Silkworm antiship missiles "will increase the potential threat to ships in the gulf." U.S. warships are adequately armed to combat the Silkworm, according to the report.

The unclassified version of the report made no mention of Pentagon consideration in recent weeks of a preemptive strike against the Silkworms, which are scheduled to become operational around July 1.

Assistant Secretary of Defense Richard L. Armitage, appearing before the Senate Foreign Relations Committee yesterday, refused to say in public session what action the United States might take if U.S. naval ships are threatened by Iran's Chinese-made Silkworm missiles. He said a preemptive strike is "something we would want to talk to Congress about" before taking any action.

Pentagon spokesman Robert B. Sims released the unclassified version of the report to reporters yesterday at the conclusion of a news conference in which he refused to discuss details. A longer, classified copy of the report was supplied to Congress earlier in the day. Security procedures outlined in the unclassified report included:Ships passing through the Strait of Hormuz or confronted by an aircraft or ship which "closes in a threatening manner" are required to fully man battle stations. While in other parts of the gulf, the ships would retain their current alert status, known as Condition Three, which requires about one-third of the crew to man weapons systems. The aircraft carrier battle group normally stationed in the Indian Ocean for seven months a year will be extended to continuous coverage "for the immediate future." The Navy will add three combatant ships to its current force of six warships and one or two support ships in the gulf.

According to the report, U.S. ships will continue to follow limited rules of engagement for attacks: "The United States will act only in the face of attack, or hostile intent indicating imminent attack against warships or commercial vessels of its flag."

The report defines hostile intent as "any aircraft or surface ship that maneuvers into a position where it could fire a missile, drop a bomb or use gunfire on a ship." Under current rules, a U.S. ship could also use its defenses if it detects radar emissions locking onto it from any weapons system that can guide missiles or gunfire.

"This includes lock-on by land-based missile systems that use radar," the report said.

Pentagon sources said that as a result of the May 17 attack on the USS Stark by an Iraqi fighter plane, the U.S. military is equipping most of its ships and aircraft in the gulf with additional electronics gear called "squawkers," which emit identifying signals. The Iraqi government has said its pilot misidentified the Stark before firing the two missiles that killed 37 sailors.

As a result of that attack, U.S. and Iraqi officials are developing improved communication procedures. The report to Congress noted that Iran "assiduously adheres to U.S.-established procedures for warning and identification when operating in the vicinity of U.S. forces," and added, "We fully intend to remind Iran of those procedures prior to implementation of the protection plan."Staff writers George C. Wilson and David B. Ottaway contributed to this report.