Soviet Defense Minister Dmitri Ustinov warned today that if the United States deploys its new MX missile, the Soviet Union will develop a similar weapon that will "in no way be inferior."

He charged that President Reagan's plan to deploy 100 new MX missiles in a Dense Pack formation in Wyoming would constitute a "crude violation" of Soviet-American strategic arms limitation agreements.

Ustinov also charged that Reagan was "deliberately misleading" the American people with his assertions about "a clear margin" of Soviet military superiority. He described as "deliberate lies" the arguments advanced by Defense Secretary Caspar W. Weinberger about the compatibility of the MX basing with the SALT agreements.

While renewing Moscow's offer for "joint and coordinated efforts to reduce the level of military confrontation," Ustinov said Dense Pack basing could "directly subvert" bilateral arms control agreements because it may eventually lead to the establishment of an antiballistic missile defense around the "area of MX deployment." This, he added, would mean a "direct breach" of the Soviet-American antiballistic missile treaty.

The fact that the entire text of his remarks was read as the main news item on the national radio and television networks tonight underscored that Ustinov was making the first authoritative statement on military matters by the new leadership.

"If the present leadership in the White House challenges us by beginning the deployment of the MX missile, then the Soviet Union will respond to this by developing a new intercontinental ballistic missile of the same class, and its characteristics will in no way be inferior to the MX," Ustinov told the government news agency Tass.

[In Washington, State Department spokesman Alan Romberg said the Soviets have already flight-tested such a missile, The Associated Press reported. He said the testing began before Reagan's Nov. 22 decision to deploy the MX in Wyoming. The Washington Post reported last week that the test ended quickly when the first stage rocket motor failed.]

"The deployment of MX missiles in a Dense Pack would be a gross violation of one of the central clauses of the Soviet-American accords, namely the commitment not to develop additional stationary launching installations for intercontinental missiles," Ustinov said. "In particular, it means a breach of article one of the SALT I treaty and article four of the SALT II treaty."

The SALT II treaty was signed by then-president Jimmy Carter and Soviet leader Leonid Brezhnev but has never been ratified. The Reagan administration, however, has pledged to abide by its provisions.

Ustinov rejected Weinberger's argument that silos cannot be equated to launchers and that they are merely shelters. Such arguments, Ustinov said, "are intended for laymen -- specialists know well that these arguments are deliberate lies."

The Soviet defense minister went into considerable detail to demonstrate the existence of "rough parity" between the United States and the Soviet Union in strategic nuclear weapons as well as in medium-range nuclear weapons deployed in the European theater. He also said that there exists "a rough parity" in conventional arms between the North Atlantic Treaty Organization and the Warsaw Pact.

Ustinov described the MX as a "weapon destabilizing the overall strategic situation" that is accompanied by the new Trident missile, strategic bombers and long-range cruise missiles "in every basing mode." By the end of the decade, he said, the United States is due to have 20,000 nuclear warheads.

The planned deployment of 572 new U.S. medium-range nuclear weapons in Western Europe, he added, would place the Soviet Union and its allies in a "dangerous" situation because these weapons would constitute "a direct addition to the U.S. strategic nuclear potential deployed on the American continent."

"All this put together," he said, "can hardly be viewed as anything short of a program of preparation for an all-out nuclear war."

Ustinov said, "We are increasingly doubtful of the sincerity of the United States and the seriousness of its intentions to reach mutually acceptable agreement at the Geneva talks on medium-range weapons."

"You inevitably come to the conclusion that the American side, taking cover behind the so-called zero option at the talks, is actually pressing for the full scale deployment of its new missiles in Europe," he said.

Reagan's zero option proposal calls for Moscow to dismantle its SS20 missiles aimed at Europe if NATO abandons plans to deploy intermediate-range missiles in Europe.

The Soviet news agency Novosti said last week that the American deployment of new missiles in Europe would force the Kremlin to switch to an "instantaneous" retaliatory posture. The so-called "launch on warning" response would trigger Soviet counterstrikes if monitoring equipment signals a U.S. attack.

While not specifying Soviet responses on that deployment, Ustinov said the Reagan administration "should not hypnotize itself with the possibility of achieving military superiority over the Soviet Union."