North Korea has told Japan it could raise the subject of wartime forced labor during Tokyo's occupation of the Korean Peninsula in any future bilateral talks, diplomatic sources have said.

The wartime labor issue has been the source of heightened tensions between Tokyo and Seoul after South Korea's top court last year ordered several Japanese companies to compensate South Korean workers for forced labor.

Japan has refused to comply with the ruling based on its stance that the matter of compensation for wartime labor was resolved under a 1965 agreement that normalized relations with South Korea. Pyongyang has repeatedly criticized this stance in state-run media.