President Reagan and Mikhail S. Gorbachev bade farewell at the Kremlin Thursday, concluding a summit long on good will but short on achievement.

Reagan told his host he had been "truly moved" by the reception he got in the Soviet Union. Gorbachev took the occasion to prod Reagan to move faster on the issues facing the two superpowers.The talks completed the most frequent superpower summits in history, four in just 30 months, underscoring the dramatic turnaround in U.S.-Soviet relations since the first meeting in 1985. Dwight Eisenhower and Richard Nixon each had three summits with their Soviet counterparts.

Air Force One took off from Vnukovo Airport in a light drizzle at approximately 11:15 a.m. local time. Reagan arrived at London's Heathrow Airport just after 11:30 a.m. local time. The president had meetings scheduled there with British Prime Minister Margaret Thatcher. Gorbachev faces, by month's end, the convening of the first Communist Party Conference since 1941.

Secretary of State George P. Shultz, who flew separately to Brussels, Belgium, to brief America's NATO allies, called the talks "a good, realistic, businesslike summit meeting."

The meetings here produced renewed vows by leaders to improve East-West relations and put into force the first-ever treaty to eliminate nuclear weapons. But tensions over regional conflicts lingered, and Reagan and Gorbachev did not advance prospects for a long-range missile treaty in any substantive fashion.

The Reagans said goodbye to the Gorbachevs in the same Kremlin hall where America's first couple was greeted on Sunday. Walking along the same red carpet in the Hall of St. George after brief remarks, the four chatted amiably and then parted company a moment later.

Raisa Gorbachev presented Nancy Reagan a bouquet of roses in what perhaps will be the last encounter for two first ladies whose relationship never was warm.

"This is an emotional moment for Mrs. Reagan and me," the president said, telling the Gorbachevs he had seen and learned much about "this Moscow spring."

Reagan said he was impressed with the Soviet people he encountered.

"At first they were curious faces, but as time went on, the smiles began and then the waves," he said, "And I don't have to tell you, Nancy and I smiled back and waved just as hard."

Gorbachev thanked Reagan for "cooperation, openness and a businesslike approach to the talks that we have had here."

But the Communist Party general secretary also said there were missed opportunities at the Moscow summit.

"Our dialogue has not been easy," Gorbachev said, "but we mustered enough realism and political will to overcome obstacles and divert the train of U.S.-Soviet relations from a dangerous track to a safer one. It is, however, so far, been moving much more slowly than is required. . . ."

In an interview on ABC-TV's "Good Morning America," Shultz said, "We had lots of things that were worked out, and we've had some very realistic, strong discussion, where we didn't agree, and that's in the nature of this case. . . . I think it's a sign of maturity and perhaps greater stability, that we can wrangle on these things and agree on other things."

Their work done, on their final night in Moscow, the Reagans went to the Bolshoi Ballet with the Gorbachevs and dined privately with their hosts at a dacha in the countryside outside Moscow. Then, the Reagans took an impromptu stroll through Red Square, which was brightly illuminated by mobile floodlights brought in by networks to provide a backdrop for their evening newscasts.

"I didn't want her to miss it," Reagan said, holding hands with Nancy.

Reagan and Gorbachev actually concluded their formal talks Wednesday _ reporting scant prog-ress on arms control and none on human rights disputes.

On his arrival at Heathrow Airport, Reagan was greeted by Foreign Secretary Sir Geoffrey Howe and a light drizzle from overcast skies. After shaking hands and waving to a small crowd under the watchful eyes of police guards armed with submachine guns, the Reagans boarded a helicopter and flew to the Winfield House residence of U.S. ambassador Charles H. Price II in Regent's Park.

Despite the lack of major agreements, Gorbachev called their meetings a "blow to the foundations of the Cold War." Reagan went to extraordinary lengths to praise the Soviet leader, seemingly absolving the Kremlin leadership for erecting barriers to emigration. He blamed the emigration walls on the Soviet bureaucracy, saying any government has that kind of problem.

It was once hoped that the summit would be crowned by an agreement to slash long-range nuclear weapons 30 to 50 percent. Instead, the leaders deadlocked on the accord and instead exchanged final papers on the treaty eliminating intermediate-range nuclear weapons.

Edward L. Rowny, a senior U.S. arms control adviser, said "we didn't get anywhere on sea-launched cruise missiles; we did not get anywhere on the SDI-ABM problem."

He referred to a disagreement over how to monitor cruise missiles carried on warships and on the link the Soviets have made between the U.S. Strategic Defense Initiative and the 1972 Anti-Ballistic Missile Treaty.