The South Korean government expressed "strong regret" over Japan's decision to recommend the controversial Sado mine as UNESCO World Heritage and has "sternly" urged for a retraction.
Sado mine is where at least a thousand Koreans were subjected to forced labor during World War Two.
Japan's foreign minister reportedly refused on Saturday calls from Korea for the retraction, while adding Tokyo wants dialogue with Seoul on the matter.
In 2015, Japanese industrial sites, including Hashima Island where Koreans were forcibly taken to work at coal mines were designated as World Heritage Sites following Japan's promise to acknowledge its use of forced labor.
But Japan is yet to fulfill its promise in this regard.