MOSCOW, JULY 1 -- U.S. special envoy Vernon Walters, seeking support for a new Reagan administration bid to forge a settlement of the Iran-Iraq war under U.N. auspices, is to hold talks on the conflict Thursday with one of Moscow's leading Middle East specialists.

He is the third prominent figure -- after former president Jimmy Carter and U.N. Secretary General Javier Perez de Cuellar -- to hold high-level talks in the Soviet capital this week on issues involving the Persian Gulf.

Today, in a Kremlin meeting with Carter, Soviet leader Mikhail Gorbachev stressed the Soviet interest in bringing about a broad peace settlement in the Middle East and hinted that Moscow favors a U.N. role as mediator there.

Amid rising concern in Washington about the increased Soviet presence in the Middle East, Gorbachev assured Carter that "the Soviet Union has no intention to infringe" on U.S. interests in the region, according to remarks reported by the official news agency Tass.

Gorbachev's remarks followed outspoken criticism of U.S. policy in the Persian Gulf by Tass, which said Washington is using the Iran-Iraq conflict "as a pretext for building up its military presence in an area in direct proximity with Soviet southern borders."

"The seat of armed confrontation can only be liquidated by stepping up collective efforts within the U.N. Security Council," Tass said.

Meeting with Carter, Gorbachev implicitly criticized the Reagan administration's approach to the Middle East. Stressing the "positive features" of Carter's policy in the region, he said that if the current U.S. administration embraced Carter's ideas, they could be considered by both sides, Tass reported. Carter, who was instrumental in forging the first Middle East peace treaty in 1979, arrived for a personal visit yesterday.

In Washington yesterday, President Reagan announced plans for a diplomatic push to help resolve the nearly seven-year-old Iran-Iraq war, but he also said he would press ahead in sending U.S. naval forces to the gulf region to protect Kuwaiti oil tankers.

Gorbachev used his meeting with Carter to stress that the Soviet Union, also invited by Kuwait to help keep order in the gulf, should be included in any Middle East peace efforts.

Reiterating Moscow's calls for an international conference on the Middle East, Gorbachev was quoted by Tass as saying:

"We understand that the United States and other western countries have interests in that region. The Soviet Union has no intention to infringe on them. Besides, this is unrealistic. The western countries, too, should not pursue unrealistic goals in pursuing the crisis."

Walters, a special ambassador to the United Nations, arrived here yesterday. He is scheduled to meet Thursday with Deputy Soviet Foreign Minister Vladimir Petrovsky and other Soviet officials, an American Embassy spokesman said, adding that the Iran-Iraq war is on the agenda.

Petrovsky, a former envoy to the United Nations, is one of the Foreign Ministry's key experts on the Middle East.

Perez de Cuellar met with Gorbachev here yesterday for talks that touched on the Iran-Iraq conflict, the U.N. secretary general told reporters.

The meetings Soviet officials are holding here this week indicate, analysts said, that Moscow may be privately bidding for U.N. forces to protect Kuwait's gulf shipping and possibly to help resolve the Iran-Iraq war.

Gorbachev and Carter focused their talks today on the Middle East, Tass said, adding that they agreed that the United Nations "should take a more active and vigorous stand in settling regional conflicts."

Kuwait asked both the United States and the Soviet Union to help protect its shipping in the war-torn gulf and they agreed, leading to a heightened U.S. and Soviet presence in the region and a greater threat of superpower conflict.

Perez de Cuellar said yesterday that his talks with Gorbachev had touched on a number of regional issues, including the wars in the Persian Gulf and Afghanistan.

Shortly after his arrival in Moscow last night, Walters met with Perez de Cuellar, a senior western diplomat said. Walters came here for talks related to U.N. business, U.S. Embassy spokesman Jaroslav Verner said today. After consulting with Soviet officials he plans to leave Saturday, Verner said.

According to Tass, Gorbachev told Carter that the Soviet Union is prepared to facilitate a Middle East conference that would take into account the interests of Israel and "all Arab countries," and would not preclude its transformation into an umbrella for other negotiations.

Carter plans further official talks before leaving.

Reuter reported from London:

Iranian President Ali Khamenei said his country now has the missile capability to make it dangerous for U.S. ships in the Persian Gulf, Iran's national news agency IRNA reported today.

IRNA said Khamenei was speaking Tuesday after watching military maneuvers in central Iran.

Khamenei was quoted as saying Iran had not possessed a missile capability until recently. He did not disclose how it acquired its new missile strength except to say "through sincere efforts all hurdles have been passed."

U.S. officials have said Iran is deploying Chinese-made missiles at the entrance to the gulf.