The White House said yesterday that differences within the administration over forthcoming bargaining on its "Star Wars" defense plan are only "a matter of terminology."

On Sunday, Secretary of State George P. Shultz and Defense Secretary Caspar W. Weinberger appeared to disagree about the relationship among the three planned sets of arms negotiations -- covering Star Wars, strategic nuclear arms and medium-range nuclear weapons.

White House spokesman Larry Speakes, seeking to clarify the U.S. posture in light of the conflicting statements, volunteered this account in a briefing for reporters:

"Interrelationships, yes" between offensive and defensive limitations -- "that was our basic position going in" to the Geneva talks. "But as far as linkage where one doesn't proceed without the other, no, that's not our position," Speakes said. "Will SDI the Strategic Defense Initiative, or Star Wars research continue? Yes, SDI research will continue. We regard it as a research program and only that. Research is difficult to verify and the Soviets agree that research is difficult to verify.

"Is deployment of SDI negotiable? It is premature to discuss that until we have our research program and decide that there is a mode for its deployment . At that time we probably would discuss it with the Soviets.

"Is agreement needed in all three talks in order to implement it in any one? That is not our view. Agreement in one or two areas would certainly be something we hope we could proceed with. The Soviets may not see it that way but we presume that would be a topic for discussion."

Asked by reporters to sum up what he had said, Speakes replied that if he were writing the story he would say, "The White House spokesman said today it is premature to discuss . . . to negotiate the deployment of SDI. The spokesman went on to say it is a research program and therefore it was too early for discussions . . . . "

Soviet Foreign Minister Andrei A. Gromyko, in a televised appearance with Soviet reporters in Moscow Sunday, said limits on offensive arms and space-defense programs such as the U.S. Star Wars program "can only be examined jointly" as part of "a single complex."

Gromyko said that "if no progress were made in space, then none could be made in the question of strategic weapons."

He seemed to concede that "scientific research work" on Star Wars cannot be monitored and thus would be difficult to limit through negotiations between the superpowers.

Gromyko maintained, though, that the U.S. delegation, headed by Shultz, "told us clearly in Geneva" that "testing" and "the stationing of facilities" in connection with Star Wars "might be prohibited."

Gromyko may have been referring to restrictions that already exist in the 1972 Anti-Ballistic Missile (ABM) treaty, in which the United States and the Soviet Union agreed "not to develop, test or deploy ABM systems or components which are sea-based, air-based, space-based or mobile land-based."

The United States has been carrying out "experiments" with devices that could be part of a future anti-ballistic missile system. But the United States has insisted that the "experiments" fall short of "tests" of an ABM "component." The Soviet Union also has been modernizing the ground-based ABM permitted under the treaty and has been conducting experiments that, according to the United States, are in the same gray area of "test" and "development."

Presidential national security affairs adviser Robert C. McFarlane, interviewed yesterday on NBC's "Today" program, said threatening statements from Gromyko about the requirements for accord on space defense were "almost laughable." He characterized Gromyko's remarks as "the kind of thing you can expect to see in the run-up to formal negotiations."

McFarlane denied that there was disagreement between Shultz and Weinberger, who appeared on different television interview programs Sunday.

Shultz had said the United States agrees "there is a relationship" between offensive and defensive arms limitations. But Weinberger said, "I don't understand that there is any degree of linkage" between implementing U.S.-Soviet agreements on offensive arms and implementing U.S.-Soviet agreements in the space-defense area.

Speakes told reporters that the difference between Shultz and Weinberger is "a matter of terminology."