Moscow — Moscow has taken a cautious public line on recently renewed talks with Peking.
The gist of the Soviet message is that there has indeed been an improvement in the atmosphere between Moscow and Peking, but that only time will tell whether this signals substantive progress toward healing the two-decade-old split between the powerful communist neighbors.
Soviet Deputy Foreign Minister Leonid Ilyichov has been meeting this month in Peking with his Chinese counterpart for exploratory talks on overall Sino-Soviet relations, the first such high-level dialogue in three years. A further round of discussions has been set for Moscow, although no date has been announced.
Meanwhile, public signs are that the Soviets want to avoid either prematurely raising expectations - or prematurely undermining prospects - for progress in the dialogue.
Moscow also seems keenly aware of the need to angle its public statements toward various concerned audiences. These include domestic party officials; the Chinese; and Kremlin allies in Asia, particularly the Vietnamese.
The most recent comment on relations with China since Mr. Ilyichov's trip to Peking has come from Konstantin Rusakov, a member of the inner Secretariat of the Soviet Communist Central Committee. Speaking at a domestic ideological conference, and quoted in Pravda, he declared:
''Along with signs that can be assessed as a desire (by Peking) to improve Soviet-Chinese relations, Chinese leaders and news media do not cease actions (proceeding) from anti-Soviet positions.
''The future will show to what extent the Chinese leadership is ready for a real improvement of relations with our country. As far as the CPSU (Soviet Communist Party) is concerned, its stand is known; it constantly comes out in favor of normalizing relations with the People's Republic of China. . . .''
By the time Mr. Rusakov spoke Oct. 13, Moscow's Chinese-language radio commentaries had virtually abandoned criticism of Peking's policy - shifting instead to reports of ''imperialist'' alarm at the prospect of eventually improved relations between the Soviet Union and China.
One commentary recommended resumption of the kind of scientific and technological relations that existed between Moscow and Peking in the 1950s - precisely the level of contact which, Western diplomats assume, Moscow hopes might emerge from the early stages of resumed Sino-Soviet talks.
The Chinese, for their part, have maintained that any genuine improvement of relations with Moscow must depend on Soviet responsiveness on various concrete political issues. These, in the stated Chinese view, include Soviet troop strength on the nations' common frontier, Moscow's military presence in Afghanistan, and Kremlin support for the Vietnamese troop presence in Kampuchea.
A Chinese source here has told a Western reporter that Moscow has delivered no substantive concession on any of these issues during Mr. Ilyichov's talks in Peking.
At the same time, Moscow has not recently repeated earlier charges that Peking was setting unacceptable preconditions for a renewed Sino-Soviet dialogue.
One European diplomat argues that the next round of talks will be an important barometer of chances for a significant improvement in relations:
''So far,'' the diplomat says, ''both sides have made it clear that they value the principle of improved relations, but neither seems anxious to deliver substantive concessions.''