MOSCOW — Soviet leader Mikhail S. Gorbachev may extend his American stay beyond the three days he plans to spend in talks with President Reagan, a Soviet official said Tuesday.
The official said that no decision has been made but that Gorbachev is thinking of spending up to five days in the United States.
Talking with American reporters on the condition that he not be identified by name, the official said some of Gorbachev's advisers believe that he should take advantage of the meeting with Reagan to convince the American people that he is a reasonable world leader. But others close to Gorbachev have cautioned that an extended visit might suggest a closer relationship with Reagan than the Kremlin wants to show at this time.
Still, the official said, moving away from the White House would give Gorbachev a chance to "appeal over the President's head" to the American people and to make clear his ideas about nuclear disarmament and Soviet-American relations.
Further details of the trip may emerge this week at meetings of top Soviet and American officials in Geneva and Moscow.
Yuli M. Vorontsov, a first deputy foreign minister, is meeting in Geneva with Under Secretary of State Michael H. Armacost and Max M. Kampelman, the chief U.S. arms negotiator. And Deputy Secretary of State John C. Whitehead is expected here Thursday for meetings with Anatoly L. Adamyshin, a deputy foreign minister, on human rights issues.
Moscow appears to be looking ahead to dealing with a new American president. Partly because of the coming changeover at the White House in January, 1989, the official said, Gorbachev has decided to defer for the time being his attacks on Reagan's Strategic Defense Initiative ("Star Wars").
This means that it may be easier to reach accord on a 50% reduction in strategic nuclear weapons without a final settlement of the space defense question, the official said. At any rate, he said, Moscow expects agreement on a second treaty before the two leaders meet again next year in Moscow.
"If President Reagan wants to visit Moscow, he had better have a treaty to sign," the official said.
Returning to the subject of Gorbachev's schedule in the United States, the official said a decision has to be made soon so security arrangements can be made.
Gorbachev and Reagan are scheduled to meet, for the third time, starting Dec. 7 to sign an agreement on the elimination of intermediate nuclear forces. They will also discuss the proposed 50% reduction in strategic weapons.
American and Soviet officials have talked about a three-day working visit, but the official said Tuesday that the length of Gorbachev's stay is still an open question. The decision may depend, he said, on how Gorbachev's wife, Raisa, feels about going to cities other than Washington.
She has accompanied her husband on every trip to the West since he came to power in the spring of 1985. She has been criticized at home for taking too prominent a role in public life.
Gorbachev intends to take at least two members of the Politburo with him to Washington--Foreign Minister Eduard A. Shevardnadze and propaganda chief Alexander N. Yakovlev. He will also have on hand members of his informal "brain trust," the official said. These include Yevgeny P. Velikhov, science adviser; Roald D. Sagdeyev, head of the Soviet space program; Georgy A. Arbatov, head of a research institute specializing in American affairs, and Anatoly F. Dobrynin, the former ambassador to the United States, who now holds a senior party post in international relations.