In the latest move in an escalating dispute between Japan and North Korea, police in Tokyo have obtained arrest warrants for two North Koreans who allegedly kidnapped four Japanese citizens in the 1970s.

Japanese officials say the two North Koreans are to be placed on the Interpol wanted list following the arrest warrants issued in Japan.

Japan and North Korea have no diplomatic relations, but have held talks recently to discuss establishing ties. But Tokyo insists that resolving the fate of Japanese abducted by North Korea's agents during the Cold War is among issues that have to be resolved before Japan will agree to formal ties.

Japanese officials say in the future they will specifically demand North Korea hand over the two men named in the arrest warrants, Sin Guan Su and Choe Sung Chol.

Sin is an honored figure in North Korea, partly because he remained loyal to the communist regime during 15 years in South Korean custody. He had been arrested there on spying charges.

The intelligence agent is accused of kidnapping a Japanese couple in 1978, for which a Japanese warrant had previously been issued for his arrest.

Choe is alleged to have abducted another Japanese couple, also in Japan, the same year.

The two couples - both of whom married in North Korea - were returned to Japan in 2002 following a summit in Pyongyang between Japanese Prime Minister Junichiro Koizumi and North Korean leader Kim Jong-il. The couples now live in Japan with their children.

Foreign Ministry spokesman Tomohiko Taniguchi says previous requests by Tokyo to turn over the men have been ignored by Pyongyang, and the warrants are meant to demonstrate Japan's resolve to bring the alleged abductors to justice.

"I am not so sure if there is any need to be polite in this case, involving kidnapping, involving the outright denial of very much apparent cases, and so we are not threatening in any way North Koreans, but we are actually urging them, repeatedly, to send back those people to Japan," he said.

Japan is also reiterating its demand that Pyongyang hand over Kimihiro Uomoto. He has been under North Korea's protection since 1970 when he was part of a Japanese Red Army group that hijacked a jetliner to North Korea. Japanese police also want to question him about the abduction of a Japanese woman that North Korea has admitted kidnapping.

Japanese government officials have been expressing increasing frustration with North Korea for its failure to give more information to Tokyo about the abductions. But Taniguchi says the timing is not a response to the stalemate in the talks between Japan and North Korea.

"There has been a precedent in which three people were identified and three arrest warrants were issued, so, no matter how it seems that these two events are correlated with one another, the one is based on investigators' calendar, and the other, diplomatic calendar, has very nothing to do with the former," said Taniguchi.

The North Korean government has admitted kidnapping 13 Japanese nationals to help train spies, and says it has accounted for all the abductees. Pyongyang has released five individuals and says the other eight are dead.