TOKYO - A joint news conference after a trilateral meeting between Japan, South Korea and the US in November was cancelled because the two Asian neighbours were at loggerheads with each other.

The United States will not be hoping for a repeat this Saturday (Feb 12), with both of them now embroiled in a fresh spat. The foreign ministers of all three countries are due to meet in Honolulu to discuss the spate of seven North Korean ballistic missile tests this year.

South Korea has been irked by the move by Japan on Feb 1 to nominate the remains of 400-year-old gold and silver mines on the island of Sado, off Niigata prefecture, for Unesco World Heritage status.

The site was the world's largest producer of gold in the 17th century, and Japan's Unesco bid was specifically meant for the Edo period ending 1868. It produced at least 78 tonnes of gold and 2,330 tonnes of silver until it was decommissioned in 1989.

It is regarded by Japan as a "rare example of industrial heritage that operated continuously on a large scale", with local Niigata records pointing to how it had boasted of outstanding mining technology for its time.

South Korea, however, has pointed to the use of forced Korean labour during the Japanese occupation of the Korean peninsula from 1910 to 1945, and Seoul contends that Japan has tried to whitewash history.

The site was also used to gather copper, iron and other key metals for the war effort, with Niigata records acknowledging the drafted Korean workforce.

The South Korean government has already launched a task force to garner support from the international community and lead a campaign to block Japan's bid.

South Korean Foreign Minister Chung Eui-yong told his Japanese counterpart Yoshimasa Hayashi during a phone call on Feb 3 that the nomination "ignores the painful history of forced labour of South Koreans".

Mr Hayashi, however, said Japan "cannot accept South Korea's one-sided argument", adding that the ball was in Seoul's court to propose solutions.

Tokyo, which has already apologised for its wartime atrocities, refuses to be drawn into "apology diplomacy". It also distrusts Seoul over what it sees as the renouncing of a 2015 comfort women agreement.

Politics also played out behind the scenes. Japanese Prime Minister Fumio Kishida, who as foreign minister in the Shinzo Abe government played a key role in concluding the 2015 pact, was initially reluctant to move forward with the nomination as was reportedly the Foreign Ministry in Tokyo.

But the Prime Minister made an eleventh hour U-turn under pressure from conservatives in his Liberal Democratic Party, including Mr Abe, who said that kowtowing to Seoul's interests would make Mr Kishida look weak. The party's secretary-general Sanae Takaichi also said the bid concerned the "dignity of the nation".

Dr Lee Seong-hyon, a visiting scholar at Harvard University, told The Straits Times that while the US wanted Japan and South Korea to get along, Washington was "hesitant to play the role of a proactive mediator".

This was borne out of a "fear of getting blamed by either side on this tricky issue", he said, adding that he saw Tokyo being "emboldened" by its confidence that it was Washington's closest ally in Asia, being in lockstep over China among other issues.

Dr James D.J. Brown of Temple University Japan told The Straits Times: "I think South Korea and Japan must try and draw a line between the different issues to ensure that their security cooperation does not get affected by disagreements over history to avoid the absurd situation of their intelligence agreement being under threat."

South Korea sees a parallel in Japan's treatment of abandoned mines on Hashima island, off Nagasaki prefecture, which was accorded Unesco status in 2015 as one of the "Sites of the Meiji Revolution" with a caveat that Tokyo properly explains the role of forced wartime labour there.

Unesco adopted a resolution last year that condemns Japan's failure to fully implement its pledge to explain how Korean labourers were coerced to work at the sites, against their will, during World War II.

Some observers believe Japan faces obstacles to this latest bid, especially after Unesco began a system last year to halt applications if objections were raised by other stakeholders. This was spurred by Japan, which had objected to China's application for records over the 1937 Nanjing Massacre to be recognised by Unesco.

A Unesco advisory body is slated to inspect the mine in the third quarter of this year and make a decision whether to add it to the world heritage list around May next year.

The fresh row is but the latest in a series of issues that bedevil Japan-South Korea relations, which have been in a state of permafrost over historical grievances and a territorial dispute.

The November news conference did not take place in the face of counter-protests by both Tokyo and Seoul after South Korea's top police official visited the Dokdo/Takeshima islets that Seoul administers and Tokyo claims.

Several South Korean court rulings last year also ordered the seizure of assets of Japanese companies like Mitsubishi Heavy Industries and Nippon Steel, whose predecessors had mobilised Korean labour.

Dr Kan Kimura, who studies Japan-Korea relations at Kobe University, told the Niigata Shimpo that he thinks the heritage recommendation and wartime atrocities "should be looked at separately", but that Japan must also acknowledge that forced labour had once worked at the site.

Still, Mr Abe wrote on Facebook that he saw South Korea as "waging a history war".

The left-leaning Mainichi Shimbun criticised this view in an editorial, saying: "Using culture for politics, with the intention of taking a confrontational attitude with our close neighbours, will in the end harm Japan's national interests, not help them."