The Soviet Union warned today that it would abandon the SALT II strategic arms limitation treaty and other strategic accords if the United States does not comply with them and indicated that President Reagan's "renunciation" of the unratified treaty is inconsistent with Moscow's goals for a U.S.-Soviet summit.

In a sharply worded statement, the Soviet government said that as soon as the United States exceeds "established levels of arms or otherwise violates the other main provisions" of SALT II or the earlier SALT I accord, Moscow "will consider itself free from the relevant commitments under the treaty."

The statement, released by the Soviet news agency Tass, was the first official response to a suggestion by Reagan Tuesday that the United States is not obliged to abide by SALT II limits because of alleged Soviet violations of the treaty. Reagan, citing "a general pattern of Soviet noncompliance," said SALT II will not dictate the structure of U.S. nuclear forces.

The Tass statement came two days after Soviet negotiators at Geneva presented a new proposal regarding the 1972 Antiballistic Missile treaty in confidential discussions with the United States, a senior administration official said in Washington Saturday night.

The Soviet proposal called for a 15- to 20-year extension of the ABM treaty, more precise definitions of permissible ABM research and definitions of other technical aspects that bear on the U.S. "Star Wars" antimissile program, the official said.

In return for such limitations on strategic defense, Soviet negotiator Viktor Karpov told his U.S. counterpart that Moscow would offer major reductions in strategic offensive nuclear weapons, but he reportedly was not specific about such cuts.

The administration official said the Soviet proposal, which was first reported in Sunday's edition of The New York Times, was the first new element introduced by Moscow on space-related weaponry at the Geneva talks since they began early last year. He added the Soviet proposal is not likely to be acceptable because permitted research is narrowly defined in such a way that it apparently would prohibit work on the Star Wars program.

The clash between the Kremlin and the Reagan administration over SALT II comes during a stalemate in U.S.-Soviet relations, compounded by opposing policies on a nuclear test ban and frustration among officials here with what they see as a lack of will in Washington to make concessions to improve the atmosphere.

SALT II, signed in 1979 by the United States and the Soviet Union but not ratified by the U.S. Senate, limits the nuclear stockpiles on both sides.

Both have adhered to the SALT II treaty since its signing, although it expired this year and Reagan administration officials have complained about what they described as Soviet violations. Reagan said Tuesday that the United States intends to go beyond the limits set by the treaty when it deploys new air-launched cruise missiles on B52 bombers, probably late this year.

The Soviet government today denied that it had violated the agreement, saying, "such assertions are unfounded from beginning to end." It said that if the United States goes beyond the limits set in SALT II, it will take "the necessary practical steps to prevent the military-strategic parity from being upset."

In Washington, State Department spokesman Edward Djerejian said, "The pattern of Soviet noncompliance is absolutely clear and, therefore, these assertions by the Soviets are baseless," The Associated Press reported.

Among the violations Reagan cited Tuesday are deployment of the SS25, a mobile single-warhead intercontinental ballistic missile, and the hiding of telemetric signals from Soviet strategic missile test launches.

Today's Soviet statement also charged the Reagan administration with taking an "unconstructive" stance on the issue of a U.S.-Soviet summit and at the Geneva arms control talks.

Soviet Communist Party leader Mikhail Gorbachev has stated certain conditions he wants fulfilled before there is a summit meeting, including an appropriate atmosphere for the meeting and "concrete results" on security issues.

"It is clear that the challenging move made by the United States in no way attests to either one or the other," the Soviet statement said.

U.S. officials have complained that Moscow has not responded to U.S. proposals to fix a date for the summit meeting.

The Soviet statement called Reagan's new position on SALT II "an outright renunciation of the treaty," and said that it "undermines the foundation of limiting and reducing" nuclear arms.

It also charged the United States with undermining the SALT treaty by not ratifying it and circumventing it through the deployment of Pershing II and cruise missiles in Western Europe.

However, the statement said, Washington's nuclear buildup "is to a certain extent restrained by the SALT agreements." The buildup, it said, includes deployment of B1B and B52 bombers with long-range cruise missiles, the development of "the new second type of ICBM intercontinental ballistic missile Midgetman," deployment of additional ICBMs and the development of an "advanced cruise missile."

But the statement flatly rejected assertions that the Soviet Union has violated SALT II or other arms treaties.

"There have not been and are no such violations," it said. "The U.S. government knows that well."

"The American side should have no illusions that it will manage to get military advantages for itself at the expense of the security of others," the statement said.