Updated

Japanese officials say Japan and North Korea have agreed to meet again after talks this week produced no breakthroughs on longstanding issues.

Foreign Ministry spokesman Masaru Sato said Saturday that the two countries acknowledged the talks in the Mongolian capital of Ulan Bator were "useful for the improvement of the two countries' relations." He said they agreed to cooperate on issues that have long strained their ties, including the abductions of Japanese citizens by North Korea in the 1970s and '80s, Pyongyang's missile and nuclear programs, and compensation for Japan's wartime past. The two countries have no formal diplomatic relations.

The meeting Thursday and Friday followed lower-level negotiations in August, the countries' first bilateral talks in four years.