Moscow — ''We still have a leader who's firmly in control. We aren't softening our stance, and don't expect us to any time soon.'' That seems to be the message coming from behind the walls of the Kremlin just days before two important events: the meeting of top United States and Soviet diplomats in Stockholm, and a major address on US-Soviet relations by President Ronald Reagan.
This rhetorical preemptive strike came in typically Soviet fashion - in a statement by Soviet leader Yuri Andropov issued by Tass, the official news agency, and in an article in Pravda, the official Soviet Communist Party newspaper.
Taken together, they left no doubt that the Soviet Union is holding to its hard-line stance on negotiations over medium-range nuclear weapons in Europe. Further, they seemed to be aimed at quashing hopes for an early thaw in frigid relations between the two superpowers.
The Soviet Union walked out on negotiations over intermediate-range nuclear weapons last November. Shortly afterward, it threw two other sets of talks - on long-range intercontinental nuclear weapons and on conventional forces in Europe - into limbo by refusing to set dates for resumption.
Since then, the Soviet Union has blamed the US for the breakdown of the talks , arguing that the stationing of new American-supplied nuclear missiles in Western Europe made further discussions with the West pointless.
Andropov's most recent statement goes even further.
''Indeed,'' he wrote, ''the danger of nuclear war increases as a result of the commenced deployment of new American missiles in Europe.''
''The United States,'' he continued, ''turned the talks in Geneva into a screen for covering up its plans of deploying at all cost the new first-strike nuclear weapons in Western Europe. And when the United States started the actual deployment of its missiles, continuation of the talks in these conditions would be tantamount to complicity in deceiving the European and world public.''
Andropov has not been seen in public for more than four months. His statement , made in response to a message from a French pacifist group called Appeal of 100, was the latest in a number of pronouncements issued in his name.
The statement may have been made, in part, to dispel suggestions that the Soviet Union is virtually leaderless because Mr. Andropov has been disabled by an undisclosed illness. Another motivation could have been to steal President Reagan's thunder before his nationwide television address on Monday, thus undercutting any initiatives he might outline before they are even presented. In his speech, Mr. Reagan is expected to express a willingness for renewed dialogue with the Soviet Union.
In the Thursday statement, Andropov repeated Soviet demands that the US and its NATO allies show a willingness to withdraw the new missiles from Europe.
He did not, however, repeat earlier Soviet demands to include the independent nuclear forces of Britain and France in the negotiations.
That task was left to the editors of Pravda, the official Communist Party newspaper. Pravda often serves as a mouthpiece for official views. In a long article that came out on the same day as Andropov's statement, Pravda said the Soviets still insist on including British and French nuclear weapons in the negotiations - something the United States has adamantly refused to do on grounds that it has no control over these missiles.
Pravda again dwelt on the theme that the US, not the Soviet Union, was to blame for the failure of the Geneva negotiations.
''Agreement at the talks was possible. The Soviet Union was prepared to go far to meet the West in order to prevent a new, very dangerous stage in the arms race. The USA has blown such a possibility, acting fully consciously. They have chosen another road, and now they are facing the consequences,'' wrote Pravda.
Some Western officials, however, say the Soviets are merely feigning wounded innocence while continuing with their own arms buildup. NATO announced this week that in the last month, the Soviet Union has deployed nine new SS-20 missiles in the eastern part of the country, most likely aimed at China. Meanwhile it continued to protest over the stationing of new American-supplied NATO nuclear missiles in Europe.
It was the targeting of SS-20 missiles on Western Europe that prompted NATO, in 1979, to plan for the stationing of new, more accurate American missiles in Europe. Otherwise, NATO leaders argued, Western Europe could be held hostage to the Soviet Union.
Mr. Reagan's speech will come on the eve of a conference on European disarmament in Stockholm, at which Soviet Foreign Minister Andrei Gromyko and US Secretary of State George Schulz will meet.
Some Soviet officials are apparently convinced that Reagan's toned-down rhetoric toward their country is timed to coincide not so much with the Stockholm conference as it is with Reagan's expected announcement that he will run for another term in office.
And the Soviets don't want to do anything to make his candidacy easier. That is one reason why they are going out of their way to scotch notions that some sort of breakthrough in relations might take place at Stockholm.
''To want Reagan to be reelected, you have to be acting on some sort of a fantasy,'' says one member of the Communist Party Central Committee.