SADO, Japan (AP) — Japan held a memorial ceremony on Sunday near the Sado Island Gold Mines, listed this summer as a UNESCO World Heritage site after the country moved past years of historical disputes with South Korea and reluctantly acknowledged the mines' dark history. However, it has not offered an apology.

South Korea’s government says it has decided not to attend a memorial service near Japan’s Sado Island Gold Mines due to unspecified disagreements with Japan over the event, which stirred longstanding tensions over the abuse of Korean forced laborers at the site before the end of World War II.

South Korea says it will not attend a ceremony in Japan to commemorate victims of forced labor in the Sado Island Gold Mines. This comes as the two nations seek to draw together amid regional threats.