MOSCOW — Soviet leader Mikhail S. Gorbachev acknowledged for the first time Monday that the Soviet Union is doing basic research similar to American scientific work for the Reagan Administration's Strategic Defense Initiative (SDI) program of space-based missile defenses.
Gorbachev, interviewed by NBC News television anchorman Tom Brokaw, said, however, that Moscow never would build or deploy a "Star Wars" system, as the U.S. program is colloquially known, and renewed his call for the United States to scrap SDI.
Even so, he insisted that SDI would not be a subject of his negotiations at his summit meeting with President Reagan next week. He said the Americans could conduct research on the missile defense program so long as it did not violate the 1972 Anti-Ballistic Missile Treaty.
Speaking a week before the Washington summit, the Kremlin chief also said there were "real prospects" for an agreement to cut by half the number of strategic nuclear weapons in the superpowers' arsenals, following their signing of a treaty to eliminate all ground-launched intermediate nuclear missiles.
As for fears expressed in the West that the removal of medium-range and shorter-range nuclear weapons would give the Soviet Union a military advantage in Europe because of its larger conventional forces, Gorbachev said: "The Soviet Union has no intention whatsoever of attacking anybody."
He added: "There is a certain asymmetry, both in forces and armaments. . . . We are ready to sit down at the negotiating table and tackle these problems . . . in a constructive way."
The hourlong interview with Brokaw, recorded Saturday and broadcast Monday evening, was the first time that Gorbachev has consented to appear on American television since he came to power in March, 1985.
Wearing a dark gray striped suit, white shirt and wide tie, Gorbachev seemed generally relaxed during the interview, but he became animated and wagged a finger at Brokaw during a lively discussion of human rights.
Gorbachev took the offensive on the rights issue, asserting that the Soviet state provides greater social protections for its citizens than the United States.
"I think there will be a lot of water passing through the Mississippi and the Volga before the U.S. Congress and the Administration recognize the American people's right to protection of their social and economic rights," he said.
On the issue of emigration, he suggested that the American protests against the denial of exit visas to Soviet Jews and others were a cover-up for the real motive of obtaining highly educated and highly skilled migrants.
"What they're organizing is a brain-drain and of course we're protecting ourselves," he said indignantly.
All those who have been refused permission to leave the country were denied exit visas for reasons of state security, he said, adding: "There are no other reasons."
Brokaw told Gorbachev at the outset that there would be time for the Soviet leader to address the American people directly at the end of the hour. But Gorbachev forcefully told the anchorman that he wanted to make such an address "before you begin to grill me."
"We need mutual understanding, and I believe that we must display greater respect for each other," Gorbachev said in the direct message to his American audience.
There were few surprises, however, as the Soviet leader sounded familiar themes on the war in Afghanistan, Soviet agriculture, emigration, developing countries and the role of women in public life.
Discussions With Wife
On a personal note, Gorbachev was asked whether he and his wife, Raisa, talked about national and international affairs with one another.
"We discuss everything," he said, refusing to elaborate.
Asked about the chances that he and Reagan would sign a treaty by next summer to halve the number of their most powerful missiles, he replied:
"I believe that, in this matter, which really does make up the very core of Soviet-American relations, there are real prospects ahead of us.
"We believe it is possible to do a lot of work with this present Administration. . . . I guess the Americans and the world at large have convinced themselves that we can and we are, indeed, acting constructively."
He said, however, that such major reductions would have to be accompanied by strict compliance with the ABM treaty, which the Soviets interpret as barring any testing or deployment in space of an anti-missile system.
"In the degree that SDI does not run counter to the ABM treaty, let America act, let America indulge in research . . . . That's not a subject for negotiations."
The Administration maintains that the treaty would permit testing but said it would abide by a more limited interpretation of its provisions for the present.
Brokaw noted that many Americans believe that the Soviets are involved in efforts to militarize space and to develop their own version of SDI.
"Well, it's really hard to say what the Soviet Union is not doing," Gorbachev replied. "Practically, the Soviet Union is doing all that the United States is doing, and I guess we are engaged in research--basic research--which relates to those aspects which are covered by the SDI in the United States.
"We will not build an SDI; we will not deploy SDI; and we call upon the United States to act likewise," he added.
If the United States goes ahead with SDI, he reiterated, the Soviet Union would find a defense, adding a dig that "It'll be a hundred times cheaper."
As for Afghanistan, Gorbachev said he wanted an early solution and if the Reagan Administration wanted the problem to be solved, it could be done "very quickly."