North Korea's latest nuclear test appears to have thawed, at least temporarily, the chilly relationship between South Korea and Japan.
The leaders of Japan and South Korea are pledging to work together to impose tougher sanctions on Pyongyang a day after North Korea announced it had detonated its third nuclear device.
The Japanese prime minister and the South Korean president held their first telephone conversation since Shinzo Abe returned to power in Tokyo in late December.
Japanese officials say Abe and President Lee Myung-bak talked for 20 minutes Wednesday and also agreed to coordinate closely with Washington in dealing with North Korea.
In Seoul, Lee is to be succeeded by President-elect Park Geun-hye on February 25.
Relations between Tokyo and Seoul have significantly cooled because of an unresolved dispute over an island (known as Dokdo in Korean and Takeshima in Japanese) held by South Korea since the early 1950s but claimed by Japan.
Speaking in a parliamentary committee meeting, Japanese Foreign Minister Fumio Kishida acknowledged concern about the possibility of another North Korean nuclear test in the near future.
The foreign minister says Japan is doing its best to collect information about whether North Korea might be preparing another test and is closely watching movements in the reclusive country.
Kishda adds that to deter Pyongyang from further provocations it is also important for Tokyo to cooperate with Beijing in regards to North Korea.
China, which is North Korea's sole remaining significant ally and holds a veto on the U.N. Security Council, is expected to allow the imposition of tougher sanctions on Pyongyang following Tuesday's nuclear test.
China had joined other nations in strongly requesting North Korea not set off another nuclear device.
Existing Security Council resolutions ban the isolated and impoverished country from conducting nuclear or missile tests.