Japanese Prime Minister Fumio Kishida has urged South Korea to carry out a bilateral agreement on settling the wartime sex slavery issue, marking the sixth anniversary of the 2015 accord.

In an interview with Kyodo News on Tuesday, the Japanese leader said that discussions are meaningless if a promise made between two countries is not kept.

Kishida was foreign minister when the agreement was signed on December 28, 2015, with his South Korean counterpart Yun Byung-se. The two announced the deal in a joint news conference that followed.

Japan insists the wartime issue is resolved following its payment of one billion yen to set up a reconciliation foundation, as stipulated in the agreement.

Tokyo believes Seoul reneged on its promise by disbanding the foundation.

In September, Kishida said bilateral dialogue is necessary but the ball is in Korea's court, reiterating there can be no future if the 2015 agreement is not upheld.