Japan will hold a memorial ceremony near the Sado Island Gold Mines, which were listed this summer as a UNESCO World Heritage site after the country moved past years of disputes with South Korea and reluctantly acknowledged the dark side of their history.

South Korea expressed regret to Japan on Monday over Tokyo's attitude towards a memorial service held for labourers including Koreans forced to work in Japan's Sado mines during World War Two, Seoul's foreign ministry said.

Japan will go ahead with a memorial ceremony on Sunday near the Sado Island Gold Mines, despite South Korea’s last-minute boycott of the event that highlighted tensions between the neighbors over the issue of Korean forced laborers at the site before and during World War II.

South Korea marked a solemn commemoration on Sado Island Monday, honoring Korean victims of forced labor during World War II at Japan's Sado gold mines. The observance, led by South Korea's Foreign Ministry,

South Korea commemorated wartime Korean forced laborers at Japan’s Sado gold mines in a ceremony Monday, a day after boycotting a similar event organized by Japan, as tensions over historical atrocities continue to strain relations between the two sides.

South Korea has expressed regret to Japan over the way Tokyo has handled the memorial ceremony for the wartime forced labor victims, including Koreans, from an old Japanese mine complex during World War II,