MOSCOW (AP) _ The Kremlin rejected a U.S. request for an exchange of televised New Year's greetings by President Reagan and Soviet leader Mikhail S. Gorbachev because superpower relations have deteriorated, a Soviet official said today.

Foreign Ministry spokesman Gennady Gerasimov, without giving specifics, also said Soviet officials plan to ''democratize'' society.

''We have no basis for the exchange of such New Year's messages,'' Gerasimov said. ''We should make joint efforts to correct the situation and have foundations for optimism.''

Last year, a taped address from Reagan was broadcast on New Year's Day at the beginning of the Soviet television news program Vremya (Time). A message by Gorbachev was shown on U.S. television.

Reagan's message marked the first time a U.S. president addressed the Soviet people on television since Richard Nixon did so during a visit to Moscow in 1972.

At his news conference, Gerasimov referred to the kind of stories reporters could expect to cover in the Soviet Union in 1987 and said:

''We are going to democratize and restructure our society and I hope you will have a lot of interesting subjects to write about this (next) year.'' Asked to provide specifics, Gerasimov advised reporters to wait and see.

Gerasimov said U.S. Ambassador Arthur Hartman approached Soviet officials with an offer to repeat the exchange of messages this year.

U.S. Embassy spokesman Jaroslav Verner confirmed today the United States ''made a proposal that an exchange similar to the one that took place last year be repeated.''

Asked if the Kremlin's refusal meant an end to such broadcasts, Verner said, ''This is a presidential thing and needs to be referred to the White House.''

He added, however: ''In general, I would say that we are very interested in an open communication with the Soviet people.''

Verner said he believed the Soviet refusal was communicated earlier to Washington. ''We did not learn about it from Gerasimov,'' he said.

Gerasimov said at today's news conference, ''Why should we create any illusion about our relations? We have no basis for the exchange of such New Year's messages.''

Gerasimov did not rule out future exchanges of televised messages.

''We believe ... that such an exchange is a good thing,'' he said. ''However, such an exchange should be in line with the spirit of our present situation. There will be no such exchange of messages this year.''

Gerasimov cited the Iceland summit as one reason for the eroding relations. Moscow says the United States reneged on tentative arms control commitments made during the summit, a charge Washington denies.

''The United States also has violated the quantitive limits of the SALT II treaty and is going to violate it by deploying a new type of missile,'' Gerasimov said.

Earlier this year, the United States exceeded limits set by the treaty when it deployed its 131st B-52 bomber equipped with cruise missiles. The 1979 pact was never ratified by the U.S. Senate.

Gerasimov said the United States also planned to develop and deploy a ''midgetman'' missile in further violation of the treaty.

He also noted that the United States has refused to join the Soviet Union's unilateral ban on nuclear weapons testing, in effect since Aug. 6, 1985. The Kremlin since has said it would resume testing after the United States conducts its first test blast in 1987.

''Unfortunately our initiatives have not been supported by the West,'' Gerasimov said. ''The West is moving in an opposite direction by spiraling up the arms race.''