Japan has sounded out North Korea about a plan to establish a liaison office in Pyongyang aimed at resolving the long-standing issue of past abductions of Japanese nationals by North Korean agents, according to sources familiar with bilateral relations.

Tokyo hopes to get to the bottom of the issue and secure the repatriation of the abductees through the plan, which was conveyed to North Korean representatives through informal contacts, the sources said Sunday.

But the outlook for a major breakthrough on the abduction issue remains uncertain as North Korea's response has reportedly been cool.