Japan proposes controversial mine in World Heritage bid

The controversial gold and silver mine complex on central Japan's Sado Island dates back 400 years and was once one of the largest of its kind in the world, according to authorities in the coastal region where it is located.

But more than a thousand Koreans were forced into hard labour at the mine during Japan's 1910-45 colonisation of the Korean peninsula, according to Seoul, which has expressed "strong regret" at the plan to seek UNESCO recognition.

Japanese cabinet members agreed Tuesday to propose the site to the UN cultural body before the end of the day, the deadline for recommendations for the 2023 list.

The well-preserved mining complex, which began operation in the 17th century and closed three decades ago, "is highly valued as a rare example of industrial heritage," top government spokesman Hirokazu Matsuno told reporters.

"However, we are aware that despite this high value, there are various discussions and opinions" regarding the bid, he added.

"We will hold cool-headed and careful discussions with the countries concerned, including South Korea, to ensure that the great value of Sado's gold mine as a cultural heritage site is appreciated."

On Friday, after Prime Minister Fumio Kishida announced plans for the UNESCO bid, the South Korean government expressed "strong regret" and summoned the Japanese ambassador in protest.

Japan and South Korea are both democracies, market economies and US allies, but their relationship has been strained for decades over Tokyo's brutal 1910-45 colonial rule of the Korean peninsula.

About 780,000 Koreans were conscripted into forced labour by Japan during the 35-year occupation, according to data from Seoul, not including women forced into sexual slavery by Japanese troops.

It is not the first time Japan's choice of UNESCO World Heritage proposal has irked its neighbour.

In 2015, more than 20 Meiji-era industrial sites were added to the list, despite initial opposition from Seoul over the issue of forced Korean labourers in the early 20th century.