Japan is working closely with the United States and China to try and defuse tensions on the volatile Korean peninsula. Officials say the government is becoming increasingly concerned about the growing confrontation between North and South Korea.
This comes in the wake of last month's terrorist bomb explosion in Rangoon, Burma, which decimated the ranks of the South Korean government's top diplomatic and economic policymakers.
The Seoul government immediately laid the blame on North Korea. Last week Burma finally concurred and severed diplomatic relations with Pyongyang.
Once the verdict was in, Japan acted quickly with punitive measures against North Korea, although these are necessarily limited by the lack of diplomatic relations. At the same time, a senior foreign ministry official said Tokyo was asking China to use all its influence on the North to exercise maximum self-restraint.
Other foreign ministry sources said the Korean issue was now expected to be high on the agenda of talks this week between Prime Minister Yasuhiro Nakasone and visiting President Reagan.
They said Mr. Nakasone would urge Mr. Reagan to use all his influence on South Korean President Chun Doo Hwan not to take any provocative actions that might exacerbate strains with the North, especially at a time when military forces on both sides of the demilitarized zone remain on heightened alert. (President Reagan will visit Seoul November 12 to 14 after completing his visit to Japan).
Sources said the Tokyo government took seriously a report from Foreign Minister Shintaro Abe when he returned from a brief visit to Seoul last month. Mr. Abe quoted President Chun as saying he was having to restrain certain elements within his military from taking immediate retaliatory action against the North for the Rangoon bombing.
Foreign ministry sources said the Tokyo government would also use all its influence to reassure South Korea that its best policy was to remain calm no matter what the provocation in order to gain international sympathy and support.
Meanwhile, a statement was issued spelling out the steps Japan was taking to express its outrage at North Korea's ''inexcusable and inhumane act.''
Japan diplomats will not be allowed to have any contacts with their North Korean counterparts abroad; no official visits will be allowed in either direction; and visits to Japan by non-governmental North Koreans would be subject to stricter scrutiny.
Japan would consult with the US on what other steps might be taken, they added. Experts predict that Japan's trade with North Korea will be cut back.