Japan has confirmed North Korea has not abandoned a 2014 bilateral agreement that led to a reinvestigation into the whereabouts of Japanese nationals abducted by Pyongyang, sources involved with bilateral relations have said.

The confirmation was made after the historic inter-Korean summit in late April, apparently during behind-the-scenes contact between Japan and North Korea, the sources said Monday.

Following the envisaged June 12 summit between U.S. President Donald Trump and North Korean leader Kim Jong Un, exchanges between Tokyo and Pyongyang over the long-standing abduction issue could also pick up pace.