Japanese police have added the names of two children missing Japan since the early 1970s to the list of people believed kidnapped by North Korean agents.
A 6-year-old girl and her 3-year-old brother were abducted near Tokyo in 1973, kept for about six months and then taken by ship to North Korea in 1974, the National Police Agency said.
The children had a Japanese mother and North Korean father - a suspected agent - and therefore had North Korean citizenship, the police said.
The mother, who also disappeared with the children, is believed to be dead, they said
North Korea admitted in 2002 that it kidnapped 13 Japanese citizens in the 1970s and '80s.
They were apparently used to train North Korean spies in Japanese language and customs.
Pyongyang sent five of them home later that year, but insisted the rest were dead.
Japan though has demanded proof and says more of its citizens may have been taken.
It has also refused to provide energy and economic aid to North Korea or normalise relations unless progress is made on resolving the issue.
North Korea made a breakthrough agreement on nuclear disarmament on February 13, raising hopes for an end to a long-running standoff with the United States and regional powers.