The new cordiality in Korea took another friendly turn today as South Korea announced it wants to resume hot-line telephone communications with the North, while the North promised to stop hostile propaganda activities against the South.

In Seoul, the South Korean capital, a government representative proposed that the two countries resume promptly the hot-line telephone conversations that were broken off three years ago.

Min Kwan Shik said someone would pick up the phone in Seoul at 10 a.m. Friday in hopes that someone would answer on the other end in Pyongyang, the North Korean capital.

In Pyongyang, meanwhile, the Korean Central News Agency declared that beginning at the same hour North Korean newspapers and radio broadcasts would stop vilifying the South.Any theatrical dramas that defame the South and tend to prolong the confrontation will also cease, it was announced.

The two pronouncements, made almost simultaneously, were the latest in a series of amiable exchanges between the two governments that have bristled with enmity for a quarter of a century.

Both sides have now agreed to the general idea of holding at least a preliminary meeting to discuss how to resume discussions on reunifying the peninsula, talks that were broken off in 1973.

The first preliminary meeting may be held in April, although the time and place have not been agreed upon.

However, the two governments are far apart in their preliminary statements of how the unification talks should be organized. North Korea wants a "whole-nation congress" that would include representatives of parties and social groups from throughout the peninsula. South Korea insists that a unification conference be attended only by government authorities.

The differences were underscored in Seoul today when Min, at a news conference, said it would be "very difficult" for a mass meeting such as the North has proposed to reach a solution to problems of reunification.

Min is acting cochairman of the South-North Coordinating Committee, the organization that held three inconclusive talks on unification in 1972-73.

He said a resumption of the hot-line conversations would be a good way to begin the preliminary talks by arranging a fourth plenary session of the coordinating committee in Pyongyang.

The hot-line was used to exchange messages until 1976, partly to arrange meetings and partly to serve as a safety catch to avert military confrontations along the Demilitarized Zone.

In Pyongyang, the government news agency said that all statements that defame South Koreans, their ideology, and their system of government would cease at 10 a.m. Friday to lessen hostility. It said it hoped South Korea would follow suit.

Both sides routinely denounce each other and exchange accusations of treachery and deceit. North Korean broadcasts usually refer to South Koreans as "imperialist lackeys" and describe the government headed by President Park Chung Hee as "the Park clique."

In Seoul, Min said that if the North Korean news agency report is true South Korea should "welcome" the change in propaganda broadcasts.

Meanwhile, another sign of the changing Korean situation has surfaced here in Japan, which since 1965 has recognized the South but not the North.

For the first time, the Japanese government has agreed to permit the entry to this country of an official North Korean delegation. Members of the North Korean Labor Party are to be admitted as guests of the Japan Socialist Party.

The concession by Tokyo has deeply angered South Korea's government, which sees it as part of a move toward equal treatment of both Korean governments.

Officials in Seoul said today they would lodge a strong protest against the Japanese policy change.