Despite the apparent progress toward a medium-range nuclear missile agreement announced by Secretary of State George P. Shultz, prospects for a summit conference between President Reagan and Soviet leader Mikhail S. Gorbachev remain uncertain, officials here and in Washington said Wednesday.
The President said in a written statement that Shultz's meetings with Soviet officials "hold promise for an agreement on intermediate nuclear forces at some point in the not-too-distant future."
He said agreements limiting strategic, or long-range, nuclear weapons, as well as the space defenses that lie at the heart of Reagan's Strategic Defense Initiative, or "Star Wars" program, "will be more difficult."
Senior officials said that before a summit is likely to be scheduled, an agreement must be reached on reduction of the medium-range nuclear missiles that are now deployed by the United States and the Soviet Union in Europe.
But presidential spokesman Marlin Fitzwater and others took pains to indicate that a summit would hinge on more than just the prospects for such an agreement. In the past, officials have said that they want to see a willingness on the part of the Soviets to deal with a wide range of issues, including long-range missiles, space weapons and human rights.
At the Iceland summit last October, the Soviets had proposed reducing arsenals of medium-range missiles to 100 warheads on each side. The Soviet Union would hold 100 in Asia, and the United States would hold 100 within its continental boundaries.
One senior White House official, speaking on condition of anonymity, said later: "We don't have any reason to be particularly negative on a summit. We just don't have anything to announce."
Soviet Foreign Minister Eduard A. Shevardnadze was quoted as saying in Moscow that it was "quite realistic" to speak of a visit by Gorbachev to Washington to sign an agreement on medium-range weapons.
But U.S. officials indicated that resolution of questions on medium-range weapons would have to wait until arms talks resume in Geneva on April 23. Fitzwater said: "The door is open. Progress was made. We don't want to rule out anything."
Before leaving Moscow to fly to Brussels and consult with allies in the North Atlantic Treaty Organization, Shultz said at a news conference that the subject of a Reagan-Gorbachev meeting was barely discussed.
Shultz said that although the issue is still unresolved, progress was made in the realm of short-range missiles. On Tuesday, the Soviets offered to dismantle their short-range missiles in Europe.
White House Chief of Staff Howard H. Baker Jr., commenting on that proposal, remarked:
"As far as I know, this is the first time they're willing to talk publicly about short-range (missiles), where they have a huge advantage, because we don't have any. So that's real progress.
"I really look forward to the pursuit of that branch of arms negotiations," he said, adding:
"The ultimate objective of the President of the United States is to see the world rid of nuclear weapons, and I therefore welcome this suggestion by the Soviet Union that they're willing to discuss not only strategic weapons, which directly affect us, and intermediate-range weapons, which were thought to be the principal subject of the discussions, and now they're talking about theater (short-range) weapons."
The Soviet proposal means "the ball is back in our court," said one senior Administration official, speaking on condition of anonymity.
Complicating the arms picture is a fourth category of weapons--tactical, or battlefield, missiles, with a range of less than 350 miles. This category, however, was not under discussion in Moscow.
'Major Forward Movement'
"This whole thing spells major forward movement between the United States and the Soviet Union that is the basis for optimism that we may be able to have historic progress in this field in the next several months," Baker told reporters.
Officials here, however, and others in Washington complained that they have relatively few details on which to base their optimism.
While in Moscow, Shultz dispatched three cables to the President and spoke with him once by telephone, Fitzwater said.
Referring to the disruption of secure communications to the United States resulting from the sex-and-spying scandal at the U.S. Embassy in Moscow, one official complained: "There's been a dearth of information coming back to us. Transmissions haven't been, shall we say, fulsome."
Shultz is scheduled to fly to California today, landing at Point Mugu Naval Air Station and then reporting to Reagan in the early evening. Baker and White House national security adviser Frank C. Carlucci are likely to attend. The President is in the midst of a weeklong Easter holiday at his ranch 30 miles northwest of Santa Barbara.