Japan has asked Interpol to put two former North Korean spies on an international wanted list for suspicion of kidnapping Japanese citizens in the 1970s.

Japan's state-run NHK TV and Kyodo News Agency said Friday that the National Police Agency made the request, but neither the agency nor the Foreign Ministry in Tokyo confirmed the report.

Arrest warrants were issued last month for the two former agents, identified as Shin Kwang-su and Choe Song-chol, on the charge of kidnapping two couples in 1978.

Both are believed to be in their 70s and residing in North Korea.

The Associated Press said the move was another step in Tokyo's efforts to pressure North Korea into disclosing more details on what happened to the abductees.

In 2002, North Korea admitted to kidnapping 13 Japanese nationals in the 1970s and 80s, apparently to train spies in the Japanese language and culture. Five including the two couples were returned, and the North said the remaining eight had died.

Japan, however, suspects abductees are still alive in the North and wants conclusive proof that the eight died. Japan has also demanded data on other missing people whom the North is suspected of kidnapping.