South Korea-Japan relations may be facing yet another downturn, with Japanese Prime Minister Shinzo Abe rejecting the South Korean government’s calls for extra measures to resolve the issue of Japan’s wartime sexual enslavement of Korean women.

Abe reportedly said during a meeting with reporters that Japan could not accept South Korea’s unilateral demands for extra measures, and reiterated his call for Seoul to faithfully carry out the agreement reached in 2015.

His remarks came after President Moon Jae-in on Wednesday also called the 2015 deal “unsatisfactory” and demanded Japan accept historical truth and offer a sincere apology to the victims in a nationally televised press conference.

Seoul’s Foreign Ministry on Tuesday said that the Korea-Japan deal on “comfort women,” a euphemism for women forced to serve as sex slaves for the Japanese military from the 1930s to the end of World War II, was flawed and failed to resolve the issue. 

The ministry, however, said it would not seek to renegotiate the deal. Instead, the government would not use Japan’s funds -- a key result of the 2015 deal -- and would use its own money to support the victims. It said it would consult with Japan on what to do with the funds already given by the country.

Foreign ministers from South Korea and Japan are to hold talks in Vancouver, Canada, next week on the sidelines of an international gathering aimed at discussing more effective sanctions on North Korea. Follow-up measures for victims of Japan’s sexual enslavement, which the Korean government called for, are likely to be discussed during the meeting.

But negotiations on how to use the funds or any extra measures for the victims are expected to face a tough road ahead as Japan remains defiant.

The two countries signed the deal on Dec. 28, 2015, to “finally and irreversibly” settle the comfort women issue, which has long been a key source of tension between the two countries. Under the agreement, Japan apologized and paid 1 billion yen ($8.9 million) to a Korea-run foundation to support the victims in return for Seoul’s promise not to raise the issue again in international forums.

Japan has maintained the issue was solved under the 2015 agreement and any attempts to amend the deal could harm bilateral ties. Following the ministry’s announcement, Japanese Foreign Minister Taro Kono said that Tokyo could not accept South Korea’s demands for additional measures. Following Moon’s remarks, the Japanese government reportedly filed a formal protest with the South Korean Embassy in Tokyo.

Moon invited Abe to attend the PyeongChang Olympics to be held here next month, but he will reportedly not attend the opening ceremony in what could be a sign of Japan’s unease over latest developments regarding the deal. Japan’s Chief Cabinet Secretary Yoshihide Suga said his participation in the games would depend on his parliamentary schedule.

The row over the comfort women deal will adversely impact Korea-Japan relations at a time when the two countries need to stand united against North Korea’s nuclear and missile ambitions, said Kim Sung-han, a former vice foreign minister.

“In theory, historical issues can be separated from security issues, but in reality, it cannot,” Kim told The Korea Herald. “The more the Korean government seeks to additionally consult with Japan on the comfort women issue, the worse its relation with Japan gets.”

But tensions are not likely to deteriorate further, given Japan’s reaction was not “stronger” than expected, another expert said.

“I don’t think Korea-Japan ties will get worse. The Korean government should communicate with the Japanese government to build mutual trust from now on,” said Lee Myeon-woo, head of the diplomacy and security strategy research department at Sejong Institute.

The deal prompted strong protests from some victims and their rights groups here. They have demanded the deal be invalidated, saying the government did not consult with them in advance and Japan’s apology was not sincere.

The victims’ resistance and negative public sentiment toward the deal led the liberal government to order a thorough review of the accord, and a public-private task force concluded that the deal, signed under former President Park Geun-hye, had procedural flaws.

President Moon pledged to renegotiate the deal on his campaign trail, but he has also vowed to normalize icy ties with Japan. He has pursued a “two track” approach of separating historical issues from current affairs to build a “future-oriented” relationship with Japan.

By Ock Hyun-ju (laeticia.ock@heraldcorp.com)