KUWAIT, JUNE 2 -- Two U.S. senators visiting Arab oil-producing states hinted here today that they had eased their reservations about an increased U.S. military presence in the Persian Gulf.

But in an airport news conference, Sens. John Glenn (D-Ohio) and John W. Warner (R-Va.) suggested that the Reagan administration should strive for what both called "long-term commitments" to Arab gulf states to restore shaken confidence in Washington and guarantee the free flow of their oil exports.

The senators, who are members of the Armed Services Committee, left here this evening for Abu Dhabi.

That will be their last stop on a visit that has taken them to Bahrain, Oman and Saudi Arabia as well as this country, which has signed a now delayed deal transferring 11 tankers to U.S. registration in the hopes of ending Iranian attacks on its oil exports.

The senators expressed a preference for a multilateral force in the region made up of U.S. Naval forces and the British and French warships that already patrol the gulf. Glenn also said he favored a United Nations role in keeping oil flowing through the Strait of Hormuz.

The senators repeatedly stressed the need for working with the nations of the Gulf Cooperation Council -- consisting of Bahrain, Kuwait, Oman, Qatar, Saudi Arabia and the United Arab Emirates.

Warner said the senators recognized the need for "further support" from the council, involving "infrastructure, additional use of facilities and the like."

"Generally speaking, they're prepared to sit down with our government and decide the specifics," he said of his high-level gulf contacts, thus hinting at greater council willingness than until now to share the risks involved in possible Iranian attacks against naval and commercial vessels flying the U.S. flag.

While insisting the senators "did not try to get a firm commitment" from council members, Glenn said they had discussed whether there "would be bases, bases we could fly out of . . . permanent basing, all kinds of arrangements, naval basing."

Glenn said past U.S. policy errors in Lebanon and Iran had raised doubts about U.S. credibility among council members.

Council countries "had a lot of problems" with the United States "coming in on a temporary basis and then leaving again," he said. "We come in and stir up a hornet's nest and leave you sitting here next to 46 million Iranians, all very unhappy with what you may or may not have done."

Nonetheless, Glenn indicated that he remained unconvinced that "reflagging" the Kuwaiti tankers was the "only way" to proceed. If Saudi Arabia or the United Arab Emirates were to demand the same protection for their shipping, "where do we stop with this?" he asked.

Their remarks were made against a background of high profile diplomacy by the Reagan administration and Iran in the gulf Arab states.

U.S. ambassadors delivered letters from President Reagan to the heads of state of Bahrain and Qatar, while high-ranking Iranian Foreign Ministry envoys sent messages to Bahrain, Qatar and the United Arab Emirates. The contents of the respective messages were not divulged.

In Damascus, visiting Iranian Deputy Foreign Minister Hussein Sheikholislam warned that rival U.S. and Soviet plans to protect Kuwaiti shipping from Iranian attack could set off possible "armed conflict between the two superpowers" because "any small mistake can lead to a big explosion."

{United Press International reported that Iranian Foreign Minister Ali Akbar Velayati met Sunday with Sheikh Zayed bin Sultan al Nahyan in Abu Dhabi and said afterward that the United Arab Emirates president had agreed with Tehran's position that a military build-up would bring further tension to the region.}

In a news conference in Washington last week, Glenn and Warner stressed their concerns about U.S. policy in the gulf.

"We're taking sides now in that {Iran-Iraq} war," Glenn said then. "We're getting away from this fig leaf of neutrality . . . . I don't want to see us in there with just a token force." Warner urged caution, saying the U.S. forces in the gulf should not be increased to a "provocative" level.