Soviet President Yuri Andropov held out the hope today that the Soviet Union and the United States may reach agreement in Geneva on limiting medium-range nuclear weapons in Europe.

The question of these weapons, he said, "has now become the nerve center of international relations" and "can become a source of a rapid and dramatic growth of the threat of new world war."

Andropov, whose remarks to a visiting American trade union leader were distributed by the official Soviet news agency Tass, said the Soviet Union had met the United States at Geneva "halfway on many points" but that the Reagan administration "continues to demand unilateral disarmament from the Soviet Union." He added, "We will naturally never agree to that."

However, Andropov told William Winpisinger, head of the International Association of Machinists and Aerospace Workers and a vice president of the AFL-CIO, "The Soviet Union will continue following a constructive and flexible line at the Geneva talks in the hope that the U.S. side will at last change its negative approach and show interest in honest agreement.

"We shall be doing so until the U.S. government, by starting to deploy new nuclear missiles close to us on the European territory, compels us to concentrate on defensive counter-measures in order to ensure the security of the Soviet people and its allies."

The tone of Andropov's remarks was mild and appeared to constitute an appeal for self-restraint. The surprise Kremlin audience granted to Winpisinger coincided with the arrival in Moscow of nine U.S. senators, all Democrats, led by Claiborne Pell of Rhode Island.

The senators, who are here as guests of the Supreme Soviet, are scheduled to confer with Andropov Thursday. Their talks are expected to focus on the current state of Soviet-American relations and specifically on the issue of medium-range nuclear missiles in Europe.

During his conversation with Winpisinger, Andropov underscored that the Soviet Union "very much needed peace" for its internal development plans and that "we want agreement [at Geneva] and reduction of the nuclear arsenals of both sides."

The Soviet leader reiterated standard charges that Washington was aggravating the situation by "irresponsible, aggressive political statements and actions." But Andropov's emphasis was on the possibility of positive developments that could break the logjam at Geneva and improve the climate in general.

Tass said the meeting took place in a "warm and friendly atmosphere" with Winpisinger giving Andropov a plaque depicting linked hands to symbolize U.S.-Soviet friendship. Winpisinger was not available for comment as he and other trade union officials left Moscow today on a tour of the Soviet Union.

Western observers noted that Andropov stressed Moscow's interest in reaching an accord at Geneva and that he spoke about possible Soviet retaliatory actions as something he would be "compelled" to order once the deployment of U.S. weapons gets under way in December.

Tass also distributed an interview tonight with Col. Gen. Vasily Reshetnikov, deputy commander of the Soviet Air Force, that was notable for the absence of standard anti-American rhetoric practiced by top military commanders in their public statements.

Reshetnikov, however, elaborated on the growing might of the Air Force which, he said, has developed a new "multi-purpose swing-wing aircraft" as well as vertical takeoff jets. He said in the past "few years" the speed of Soviet aircraft was increased by 2.5 times while supersonic jets are capable of reaching altitudes of more than 19 miles.

He described as "the backbone" of the Soviet Air Force unspecified planes carrying nuclear missiles and equipped with "modern navigational equipment" as well as "technology enabling them to detect the enemy and control fire."

The general said the range of airplane-based missiles allows the Air Force "to hit enemy targets without entering the air space in which they may be reached by enemy air defenses."