Secretary of State George P. Shultz said yesterday that Soviet leader Mikhail Gorbachev could "wait too long" before agreeing to another summit meeting, causing the Reagan administration to decide it was too late for a new round of top-level superpower diplomacy.

Shultz made the comment on NBC News' "Meet the Press," a day after returning from a Moscow meeting at which Gorbachev unexpectedly balked at setting a date for a summit meeting with President Reagan this fall.

Asked to amplify his comment, Shultz said: "This administration ends in January 1989. And as you get into the heat of the election campaign, it's no time for a Soviet leader to be here."

Responding to charges that the administration has weakened its bargaining position by being too eager for a summit this fall, Shultz noted that Soviet Foreign Minister Eduard Shevardnadze -- rather than anyone on the U.S. side -- had proposed a statement issued here in September that summit dates for this fall would be established during Shultz's trip to Moscow last week.

Shultz also noted that Gorbachev brought up the summit question at Friday's Kremlin meeting.

U.S. officials differ about whether last Friday's surprise developments are a serious complication for another summit meeting or only a temporary delay.

Kenneth Adelman, director of the Arms Control and Disarmament Agency, who is among those who believe the delay will be only temporary, said a senior Soviet Foreign Ministry official told him during the Moscow mission last week that all work on an intermediate-range nuclear forces (INF) treaty must be completed by Nov. 15 because a summit meeting to sign it will be held shortly thereafter.

Adelman said the official made the comment twice, both times before the climactic Friday meeting of Gorbachev and Shultz. On the basis of what he observed, Adelman said, he still believes Gorbachev is likely to come to Washington for the summit before the end of the year.

National security affairs adviser Frank C. Carlucci said on ABC News' "This Week With David Brinkley" that it is "quite clear that an INF treaty is within reach," with completion likely "within a matter of weeks." Carlucci attended the talks with Gorbachev last week.

If Gorbachev doesn't want to come to the United States to sign it, said Carlucci, "we can sign it somewhere else."

Shultz and Carlucci said Gorbachev's stated objections to setting the date last week for a Washington summit seemed connected with his longstanding opposition to Reagan's Strategic Defense Initiative antimissile program. Both said Reagan would not change his stand.