President Reagan has closed the door in next week's talks between Secretary of State George P. Shultz and Soviet Foreign Minister Andrei A. Gromyko on any deals that would limit his "Star Wars" missile defense program, White House officials said yesterday.

The officials said it is too early to limit ongoing research on the missile defense program, known as the Strategic Defense Initiative, and premature to negotiate any restraints on deployment, which would be many years in the future.

At the same time, officials said the United States is prepared to demonstrate "flexibility" on limiting offensive arms such as missiles carrying nuclear warheads when the Geneva discussions convene.

Officials also gave further indications of how the administration hopes to structure the detailed negotiations it hopes will follow the Shultz-Gromyko talks. There would be two sets of negotiations, one on offensive weapons, the other on defensive.

But within the offensive weapons talks, a distinction would be maintained between strategic or longer-range weapons and the intermediate-range missiles that are of most concern to U.S. allies in Europe. In the past there have been separate negotiations on these two kinds of weapons, and the administration does not want to merge future talks entirely, officials said.

In addition, the officials said that on the defensive side the administration hopes to discuss not just the space-based weapons of most concern to the Soviets, but ground-based antiballistic-missile systems, in which the United States feels the Soviets may have violated existing agreements.

The administration's public description yesterday of its plans for the talks next week was the latest in a series of such utterances by both sides, aimed in part at public opinion.

The new description seemed geared to demonstrate that, even as it negotiates with the Soviets, the administration will hang tough on contentious issues.

The administration's renewed emphasis on the importance of continuing Reagan's antimissile defense program will presumably disappoint the Soviets, who have strongly criticized the $26 billion Star Wars effort and made it clear that their top priority in arms control negotiations would be to limit or eliminate it.

Reagan's national security affairs adviser, Robert C. McFarlane, told reporters yesterday that "our negotiators will be flexible and patient" in the Geneva talks. He said the United States will offer "constructive ideas" to the Soviets, but said the meeting is only "a start down the long road" of arms control negotiations that may require "considerable time" to produce results.

McFarlane indicated that the most desirable result from the meeting in Geneva on Monday and Tuesday would be to restart the previously stalled arms control negotiations with the Soviets.

His comments came after Reagan reached final decisions this week on he U.S. positions for the meeting. In an unexpected twist, McFarlane is to be included in the U.S. delegation along with Shultz, veteran arms negotiator Paul H. Nitze and U.S. Ambasssador Arthur A. Hartman, among other officials.

A senior White House official, speaking at the same briefing under the condition that he not be identified, indicated that Reagan has instructed Shultz not to show any flexibility in Geneva on the Strategic Defense Initiative, a system that, if fully developed, may be able to shoot down missiles before they reach their targets.

"It is not a bargaining chip," the official said.

Many critics of the program in the United States have expressed doubt whether such a missile defense system can ever be successfully developed, and, if it could be deployed, whether it would ever be capable of stopping all incoming missiles.

But Reagan, who proposed it in March 1983, is said by officials to be firmly in favor of moving ahead on research. Underscoring the administration's determination not to give ground to the Soviets, the White House yesterday released a statement by Reagan hailing the concept as eventually allowing the superpowers to reduce sharply or eliminate nuclear-tipped ballistic missiles.

"Through the SDI research program," Reagan said, "I have called upon the great scientific talents of our country to turn to the cause of strengthening world peace by rendering ballistic missiles impotent and obsolete."

The senior White House official said research on the antimissile defense system, which the administration is now conducting, is a "sensible" step, and that "it would probably be impossible to negotiate terms of deployment right now" since the actual deployment apparently is many years away.

The official also stressed Soviet spending for defensive systems, such as air defense radars and antiballistic-missile launchers, that he said "calls into question the spirit if not the letter" of Soviet compliance with the 1972 Antiballistic Missile Treaty. The administration contends that research on its missile defense system is within that permitted by the ABM treaty.

Another senior official summarized Reagan's position on Star Wars this way: "It's on the table for discussion and negotiation, but not to give away." On a related issue, officials said that Reagan has ordered that the United States not offer any moratorium on testing of antisatellite weapons. There has been discussion within the administration of such a moratorium as a possible U.S. concession in later arms bargaining with the Soviets.

But the senior official said yesterday that Reagan believes such moratoriums have not worked in the past, recalling a ban on atmospheric nuclear tests that the Soviets broke in 1961.

A second White House official said Reagan is "closing the door" on giving away both the missile defense system and the antisatellite testing.

Officials have said in recent days that the United States will suggest the resumption of two categories of arms negotiations: offensive weapons and defensive weapons.