BEIJING (Kyodo) Japan on Tuesday urged North Korea to return immediately to the six-party negotiations on its nuclear threat, but Pyongyang didn't make any promises, the Japanese ambassador in charge of the issue said after bilateral talks in Beijing.

"We strongly (told North Korea) that it is important to return to the six-party talks in a swift manner," Tadamichi Yamamoto told reporters after a morning meeting. "The other side acknowledged the importance of the six-party talks, but did not say it will return immediately."

They also discussed the issue of Japanese nationals abducted by North Korean agents but failed to narrow any of the gaps, Japanese delegates said.

Japan is demanding North Korea provide concrete evidence of what happened to the abductees and return any still in the country. Tokyo also wants Pyongyang to hand over the agents responsible for the kidnappings.

At issue is the fate of 11 Japanese abducted by North Korean agents in the 1970s and 1980s.

Pyongyang claims eight Japanese died in North Korea after being abducted or having gone there voluntarily, and that two never entered the country. North Korea hasn't yet discussed the 11th person, who was added to Japan's list last April.