Kerry Urges S. Korea-Japan to 'Put History behind them'

U.S. Secretary of State John Kerry Thursday called on key Asian allies South Korea and Japan to improve their deeply strained relations and work together for regional stability.

"It's up to Japan and the Republic of Korea to put history behind them," Kerry told a joint press conference after talks with his South Korean counterpart Yun Byung-Se.

"It is critical at the same time that we maintain robust trilateral cooperation particularly in the face of North Korea's nuclear threat."

Although reining in North Korea's nuclear program topped Kerry's agenda during his brief visit, the currently toxic state of Seoul's ties with Tokyo are also a matter of concern to Washington.

"There is no question but that positive relations between Japan and its neighbors are in the best interests of the United States, the region and the two countries themselves," Kerry stressed.

He highlighted how Japan and South Korea -- Washington's top allies in the Asia region -- had much in common such as developed economies and shared values.

South Korea and Japan are the main U.S. military allies in Asia, and both are members of stalled six-party talks on North Korea's nuclear ambitions.

"We urge both of them to work with us together to find a way forward to help resolve these deeply felt historic differences that still have meaning today," Kerry said, adding he had also raised the issue with Japanese Foreign Minister Fumio Kishida during talks in Washington last week.

Although Kerry is not in a position to "broker a deal or mediate" between the two countries, "he will certainly encourage his counterparts to ... effectively manage tensions and to ensure continued and enhanced cooperation," a State Department official said earlier.

Kerry met first in Seoul with President Park Geun-Hye, who has ruled out any summit with Japanese Prime Minister Shinzo Abe until he takes steps to address South Korea's historical grievances.

Japan's 1910-45 colonial rule over the Korean peninsula remains a hugely emotive issue in South Korea, which feels successive Japanese governments have failed to apologize properly or atone for abuses committed during the period.

Following Abe's visit to a controversial war shrine in December, his already low favorability rating in South Korea plunged to the same level as North Korean leader Kim Jong-Un, a recent survey showed.

Yun reiterated on Thursday that Japan must make the move to resume the dialogue and "must take appropriate measures to improve the situation".

Japanese politicians however express exasperation at Seoul's repeated requests for contrition, pointing to numerous apologies and a 1965 agreement that normalized relations and included a large payment.

The two countries are also involved in a territorial dispute over a tiny set of islets, currently controlled by South Korea.

President Barack Obama is to visit both Japan and South Korea during a tour of the region in April.