North Korea said Friday that it would reopen an investigation into abductions of Japanese citizens, reversing its longstanding position that the issue had been settled.

In return, Japan announced that it had agreed to lift some sanctions imposed on the North for its nuclear program, including the ban on travel between the countries, but that more serious sanctions would stay in place.

The Japanese announcement, which followed two days of bilateral talks in Beijing this week, was the first sign in years of even a slight thaw between the countries. Although both sides made very minor concessions, they offered a possible way to resolve the abductions dispute, which has long complicated the six-nation talks over the North’s nuclear weapons program and has strained the relations between the governments in Tokyo and Washington....

For decades, the North denied responsibility for the disappearance of Japanese citizens in the 1970s and 1980s, despite Japanese news reports that agents had been spotted on Japanese soil.

But during a visit to Pyongyang in 2002 by former Prime Minister Junichiro Koizumi, the North’s leader, Kim Jong-il, admitted that North Korean agents had kidnapped 13 Japanese as part of a program to train Japanese-speaking spies.