Kremlin leader Yuri Andropov has vowed explicitly for the first time to remove ''dozens'' of new Soviet missiles under an earlier proposal barring planned basing of new US rockets in Europe.
He added that should Britain and France ''later'' scrap their independent force of some 160 missiles, Moscow would remove all of its recently deployed rockets from the European continent.
''The ball is now in the Americans' court,'' he said, referring to Soviet-US talks in Geneva on European nuclear forces.
He coupled the offer - the most important refinement to date of existing proposals rejected by NATO as one-sided - with the announcement that Moscow had begun testing its own radar-elusive cruise missile as a reply to the US deployment plans. NATO intends to site 572 new nuclear projectiles, most of them cruise missiles, in Western Europe beginning late next year.
(According to reports, British Prime Minister Margaret Thatcher and French Foreign Minister Claude Cheysson both rejected the Soviet proposals, saying it would perpetuate missile imbalance in Europe.)
Mr. Andropov's remarks came Tuesday in his most detailed policy speech since succeeding the late Leonid Brezhnev six weeks ago. The occasion was the 60th anniversary of Soviet statehood.
In keeping with Mr. Andropov's early leadership style, his speech was relatively succinct - lasting barely an hour.
On the domestic front, Andropov reaffirmed his early stress on the need to revamp the nation's chaotic transport system but avoided any major departures from Brezhnev-era policy. At one point, Andropov said, to a burst of applause in the Kremlin Palace of Congresses: ''Action rather than rhetoric is what we need today.''
On foreign policy, too, the overall line was one of continuity with recent policy - vowing to keep pace with new US armaments but stressing that Moscow would prefer a negotiated reversal of the superpower arms race.
Yet Andropov's tone was somewhat less rhetorically charged than Brezhnev's last speeches. After disclosing the Soviet cruise missile test and repeating a pledge by Defense Minister Dmitri Ustinov to match the planned American MX missile with a similar weapon, Andropov declared:
''These are not threats at all. We are wholly averse to any such course of events. . . . But it is essential that those who shape US policy, as well as the public at large, should be perfectly clear on the real state of affairs. . . .''
And Andropov did announce an important refinement of Soviet arms proposals - one foreign diplomats saw as likely to hike pressure on the West to meet Moscow's objections to Reagan administration offers.
Washington has in effect said: We will scrap our plans to deploy 572 new missiles in Europe if Moscow scraps its entire force of analogous medium-range rockets.
Western officials are especially intent on securing removal, and not just repositioning to the Asian part of the Soviet Union, of newly deployed, mobile SS-20 missiles capable of hurling three warheads each with pinpoint accuracy.
Moscow has raised these objections:
* The scrapping would include missiles targeted not at Western Europe, but at China.
* Even if new US missiles don't get deployed (the US so far has no European-based equivalent to the roughly 200 Soviet SS-20s in Europe) 162 British and French missiles would remain.
* The US proposal omits American ''forward-based systems'' in Europe, specifically nuclear-capable aircraft.
The Brezhnev leadership's counteroffer was to reduce medium-range carriers on the European continent to about 300 for each side, including the British and French missiles and US aircraft.
Andropov went further - specifying in effect that 162 of the remaining systems would be nuclear missiles - precisely the British and French total. So far, the United States, France, and Britain have rejected inclusion of these missiles in the Western total, in that they are not designed to protect other European countries in case of conflict with the Soviet Union and are not equal to the SS-20.
Andropov added the missile accord ''must'' be accompanied by agreement ''on reducing to equal levels on both sides the number of medium-range nuclear-delivery aircraft'' - that is, the US forward-based systems. He left open whether the reduction of the Soviet missile force in Europe would be met by scrapping rockets, or by moving them to Asian sites from which, NATO maintains, they could still reach Western Europe.
What he did say explicitly was that the reduction would cover ''dozens of the latest missiles known in the West as SS-20s,'' rather than merely older vintage rockets that Moscow has gradually been retiring.
The breakdown of the missile component in the Soviets' proposed arms accord seemed to mean Moscow would reduce European-based SS-20s by about 40, from roughly 200 to 162.
The accompanying ''stick'' was that Moscow has begun testing its version of the sophisticated US cruise missile.
Brezhnev vowed earlier this year that new US missile deployment in Europe would trigger an ''analogous'' threat to US territory. At the time, senior officials said privately this referred to Soviet development of a cruise missile that could be deployed at sea close to US shores. Before Brezhnev's passing, a senior source also told the Monitor Moscow had begun testing such a weapon.
Andropov did not, however, explicitly repeat Dec. 21 the pledge of an analogous challenge in response to US missile deployment in Europe.