Tokyo will demand that Pyongyang investigate additional cases of missing Japanese nationals if Tokyo formally recognizes them as abductees, a senior Foreign Ministry official told a Lower House subcommittee Wednesday.

"We have conveyed our intention to North Korea," said Mitoji Yabunaka, who negotiated with North Korean officials in last week's talks in Pyongyang.

Yabunaka, director of the Asian and Oceanian Affairs Bureau, made the remark as he detailed his visit to Pyongyang before the Lower House Foreign Affairs subcommittee on North Korean issues.

The government is cooperating with the National Police Agency, exchanging information with relevant countries and asking for information from people who have fled North Korea to another country, Yabunaka said.

In January, relatives and a support group involved in the search for 13 Japanese who vanished between 1968 and 1991 filed abduction complaints with local police where they disappeared.

The families claim the 13 missing Japanese were spirited away by North Korean agents.