President Reagan said yesterday that a possible summit meeting later this year with Soviet leader Mikhail Gorbachev is "a little up in the air right now" following U.S.-Soviet talks in Moscow but that he hasn't ruled it out.

In an interview with European television correspondents, Reagan acknowledged that "we were hoping {the Soviets} would set a date" for the summit when Secretary of State George P. Shultz was in Moscow last Thursday and Friday.

He added, however, "I don't think it was a diplomatic setback" that no date was fixed, "and whether it was a maneuver or not, I wouldn't have an answer to that."

Asked during a picture-taking session with congressional leaders whether Gorbachev is playing games with summitry, Reagan quipped, "If he is, he's playing solitaire."

Administration officials continued to express puzzlement about Gorbachev's refusal to set a summit date in a meeting with Shultz Friday, despite an earlier Soviet promise to do so at that time.

"A summit has not been foreclosed," White House spokesman Marlin Fitzwater said. Asked if Reagan would agree to meet Gorbachev in a third country to sign an intermediate-range nuclear forces (INF) treaty, Fitzwater said Reagan expects the meeting to be held in the United States.

He added, "Let me put it this way: If we get an INF agreement, we think there ought to be a way to get it signed."

A senior State Department official said a careful review of U.S. conversations with Foreign Minister Eduard Shevardnadze and other Soviet officials uncovered no hints before Friday's meeting that Gorbachev would balk at setting a date.

"I think it's fair to say we don't really know why" Gorbachev backed away, Fitzwater said.

Reagan, speaking to the European journalists, said, "I don't think that it was a deliberate negative because I think they would have simply said they weren't going to be" attending a summit if that were the intention. Reagan's remark suggested he may have accepted the theory that Gorbachev may have unintentionally overplayed his hand in the meeting with Shultz.

If Gorbachev's reason is to pressure Reagan to limit his space-based Strategic Defense Initiative, Fitzwater said, "I hope the general secretary did not make a miscalculation in underestimating the president's resolve" on this issue.

Reagan reiterated to the European journalists that he will not allow SDI to become a bargaining chip in arms control negotiations. But he also said, "There may be some maneuvering on deployment and so forth."

Though they disagree on many other points, U.S. and Soviet officials agree that deployment of a futuristic antimissile system such as SDI is barred by the 1972 Antiballistic Missile Treaty as long as it remains in effect.

The Soviets have proposed a 10-year period of nonwithdrawal from the ABM Treaty. Reagan at the Reykjavik summit last October proposed a 7 1/2-year nonwithdrawal period and eventually agreed to a 10-year period, but in both cases the U.S. proposals contained stringent and far-reaching conditions.