MOSCOW, NOV. 10 -- Soviet leader Mikhail Gorbachev could prolong his upcoming visit to the United States several days beyond the three days now planned, a senior Soviet official said today.

U.S. spokesmen have said the Gorbachev trip, scheduled to begin Dec. 7, is due to end Dec. 10 or 11, but Kremlin officials are weighing a longer stay, the Soviet official, who asked not to be named, said.

Other Soviet officials have indicated that besides the length of Gorbachev's visit, his program and general objectives and entourage are still the subject of intensive senior-level discussions at the Kremlin.

Besides signing a U.S.-Soviet accord to eliminate medium- and shorter-range missiles, Gorbachev's general purpose is expected to be making sure that the disarmament process will continue beyond the summit and beyond the Reagan presidency.

One Soviet official said Gorbachev's trip could focus as much on engaging the American people in a discussion of disarmament as on meetings with officials. Vitaly Korytich, editor of the official magazine Ogonyok, said in an interview that "the trip has other important purposes besides the talks."

In the Soviet view, the Washington summit should involve a major discussion of a treaty to cut back on strategic nuclear arsenals on both sides and to abide by the 1972 Anti-Ballistic Missiles (ABM) treaty, in addition to signing the treaty on intermediate nuclear forces (INF).

"The summit could give a real impetus to relations if it is followed by other initiatives for disarmament," Kremlin foreign policy adviser Evgeniy Primakov said in an interview. "We don't see the summit and the agreement to be signed there as the end of a process but part of a long process in our relations."

The INF treaty to be signed and the strategic weapons treaty under discussion are "not linked but they are also not separate," said Primakov, head of the International Institute for the World Economy, a leading Soviet think tank. Both agreements are part of a larger disarmament process, he added.

"The main job of Moscow is to ensure that Reagan is engaged in the arms control process until the end of his presidency," an expert on American affairs said in a recent interview. Besides planning meetings between Gorbachev, President Reagan and other senior officials, Kremlin aides are also discussing Gorbachev's agenda during the trip, including possible public relations appearances or sightseeing trips.

Raisa Gorbachev, who is expected to accompany her husband on the trip, also is involved in discussions about possibly extending the visit, according to a Soviet source. She favors a visit of longer than three days, the source said.

Soviet officials stress that the trip is a working visit. They also have mentioned the possibility that Gorbachev will make a major speech before Congress or the U.N. General Assembly.

The team of aides to accompany Gorbachev will include Foreign Minister Eduard Shevardnadze and propaganda specialist Alexander Yakovlev, both members of the ruling Politburo, Soviet officials have said. Other members of the Soviet delegation are still under discussion, an official said, and could include Defense Minister Dmitri Yazov.

Beginning senior-level presummit talks, Deputy Secretary of State John Whitehead is to arrive here Nov. 14 for discussions with Deputy Foreign Minister Anatoly Adamishin on human rights issues.

Deputy Foreign Minister Yuli Vorontsov and Undersecretary of State Michael Armacost are to meet on regional issues in Geneva Nov. 17 and 18. In addition, Vorontsov and Max Kampelman, who heads the U.S. delegation in Geneva, are scheduled to hold talks Nov. 16.

Both sides agree that the INF treaty is largely finished and the Geneva negotiations will focus on wrapping up the remaining details, Soviet officials here have said.

Although many Soviet officials are convinced Reagan is interested in arms control to enhance the record of his term in office, they have expressed fears that after signing an INF accord he will abandon the disarmament process and delay negotiations for follow-up agreements.

Uncertainty about Reagan's commitment to postsummit disarmament negotiations, apparently a subject of major dispute in the Kremlin, is seen by some as a possible reason for Gorbachev's sudden -- and shortlived-reluctance to set a date for a summit during meetings last month with Secretary of State George P. Shultz.

At the start of an Oct. 23 meeting with Shultz, Gorbachev indicated to journalists that he would be going to the United States for a short visit. But about three hours after the meeting started, he told Shultz he was not prepared to go.

There has been speculation here that Gorbachev decided during the meeting that the United States was not prepared to discuss the question of Reagan's Strategic Defense Initiative, a program for a space-based antimissile system, and thus decided suddenly to delay setting a summit date.

According to a U.S. official present at the talks, when Gorbachev told Shultz he was not comfortable fixing a summit date, he added that he would have to consult with Kremlin colleagues before setting one.