The Soviet Union said tonight that its negotiations with the United States on reducing strategic or long-range arms have reached a dead end and charged that the Reagan administration "is totally responsible for the stalemate at the talks."

"The point at issue" at the talks in Geneva on these intercontinental weapons, the Communist Party newspaper Pravda said, is whether the two sides can reach agreements on controlling strategic armaments or, failing that, resign themselves "to the fact that the nuclear arms race will be continued and elevated to a new, dangerous stage."

The massive Pravda editorial, which was distributed by the government news agency Tass prior to its publication Sunday, accused Washington of "hampering and actually obstructing the talks." It said the Soviet Union "will not permit" the United States to gain "unilateral military advantages."

Restating Soviet insistence on "parity, equality and equal security" as "the unshakable basis" for any strategic accords, Pravda quoted Soviet leader Yuri Andropov's publicly voiced hopes that the United States would make "a manifestation of good will" to move the talks off dead center.

"The question now is if the United States side is prepared to embark on the road toward an agreement," the editorial said.

Its critical and pessimistic tone came as a surprise to some western analysts here after Andropov two days ago publicly voiced the hope of a possible compromise in Geneva.

The Soviet leader, responding to questions cabled by an U.S. journalist, said he would be prepared to meet with President Reagan in an effort to improve Soviet-American relations. He made no critical references about the Geneva talks and said, "Objectively speaking there is every possibility" for a compromise there.

The United States has proposed cutting long-range nuclear warheads by about one-third, while Andropov has suggested a 25 percent cut.

"The American approach, and this is visible literally in all of its elements," the Pravada commentary said, "is not a way of reaching a mutually acceptable agreement but a plan for a unilateral disarmament of the Soviet Union that is camouflaging as a proposal on reductions" of strategic arms.

The Reagan administration's objective, it added, is to ensure the United States "the superiority it once had in the strategic field."

An unsigned editorial in Pravda is one of the main vehicles used by the Kremlin leadership to make major policy pronouncements.

The editorial underscored the often stated view here that the Soviet Union would match any new American weapons program to maintain strategic parity and that it was not prepared to seek arms control accords at any price.

But the editorial also appeared to reflect a privately voiced view here that Soviet-American relations have entered a crucial stage and that some breakthrough in Geneva should come soon if a new round in the arms race is to be avoided.

The 2,500-word editorial constituted the most comprehensive review to date of progress at the Geneva talks, which began in June. It did not contain any new proposals and the only apparent new element was the assertion that Moscow, in advancing its earlier proposals, had taken into consideration the fact that the United States has "forward-based nuclear means" deployed near the Soviet border.

The Soviet commentary also publicly disclosed some details of the proposals the Kremlin has advanced at the Geneva talks. It charged that the past two rounds of strategic arms reduction (START) talks and other U.S. actions "have shown that Washington is interested in preserving a position of impasse at the talks rather than in advancing them along constructive lines."

This impression is reinforced, Pravda said, by Washington's intention to deploy 572 new medium-range nuclear weapons in West Europe at the end of the year. These weapons are the subject of parallel negotiations being held in Geneva.

Pravda said that the United States has "at its disposal forward-based nuclear means deployed in close proximity" to the Soviet borders and that "these weapons are of a strategic character" for the Russians. "We do not have such means close to the territory of the United States."

The Americans, Pravda said, while suggesting cuts in intercontinental missiles based on land and sea and in heavy bombers, intend to build up "other nuclear means which are capable of reaching objectives" on Soviet soil.

By this, it said, the United States is "undermining the very fundamentals of a future agreement."

The editorial pointed out that the 1979 treaty resulting from the Strategic Arms Limitation Talks, or SALT II, which was not ratified by the United States, essentially established equal ceilings on long-range missiles, bombers and nuclear warheads. It said Reagan's proposals place the main burden on the Soviet Union, which would have to make deep cuts in its land-based missiles force.

Under Reagan's proposal, Pravda said, the Soviet Union would have to dismantle "more than 90 percent of all of its intercontinental ballistic missiles which are known to make the basis of the Soviet Union's strategic defense might." The aim of the plan, it added, is to "ensure by hook or by crook" a weakening of the Soviet defense potential.

While advocating reductions in the number of warheads carried by missiles, Pravda said, the United States intends to place 4,000 long-range cruise missiles on Air Force heavy bombers. "This would actually not constitute a reduction but a considerable increase in the number of nuclear charges in strategic carriers," Pravda said.

The editorial said that the Soviets at Geneva proposed a 25 percent cut in the number of land- and sea-based intercontinental missiles and heavy bombers. The number of nuclear warheads carried by these systems should be reduced to "equal agreed levels," it added.

The editorial asserted that the United States has "stubbornly declined" to accept the Soviet approach. It maintained that the Americans have refused to discuss similar confidence-building measures advanced by the Russians earlier in the talks. These included:

* A ban on flights of heavy bombers and the cruising of aircraft carriers in "agreed zones adjoining the territory of the other side."

* Advance notifications of a mass takeoff of strategic and forward-based aircraft.

* Establishments of zones for missile-carrying submarines in which "antisubmarine activities of the other side would be banned."