Photo/IllutrationForeign Minister Taro Kono fields questions from reporters at the Foreign Ministry on Jan. 9 after the South Korean government announced its new policy toward the "comfort women" issue. (Nobuhiko Tajima)

Tokyo lashed out at Seoul's call for Japan to make further efforts to restore the dignity and honor of former "comfort women," but refrained from taking the hard-line step of recalling its ambassador to South Korea.

It insisted that South Korea respect the terms of a landmark 2015 bilateral agreement, which the two countries labeled as having "finally and irreversibly" resolved the issue that had proved a thorn in bilateral relations for decades.

Despite its strong reaction to Seoul’s new posture on the issue of women forced to provide sex to wartime Japanese soldiers, Tokyo decided not to recall its ambassador due to a pressing need for the two neighbors to cooperate in the face of North Korea's repeated ballistic missile and nuclear tests.

Instead, Japan urged South Korea to steadily implement the accord under which Japan provided 1 billion yen ($8.88 million) to a foundation set up in Seoul to assist former comfort women.

Foreign Minister Taro Kono, meeting reporters, drove home the importance of committing to the deal reached with the previous administration in South Korea.

“The Japan-South Korea agreement is a promise between the two countries and must be implemented responsibly even if a new administration comes in,” he said. “It is totally unacceptable for Seoul to call for additional measures from Tokyo.”

Kenji Kanasugi, director-general of the Japanese Foreign Ministry’s Asian and Oceanian Affairs Bureau, filed a strong protest the same day by summoning Lee Hee-sup, a minister at the South Korean Embassy in Tokyo.

At a news conference earlier in the day, South Korean Foreign Minister Kang Kyung-wha said Seoul will respect the agreement, but expressed her hope that Japan will “act on its own initiative to offer a heart-felt apology” to the victims.

In the historic accord, Japan acknowledged its responsibilities toward the former comfort women as Japanese military authorities were involved. It stated that Prime Minister Shinzo Abe offered his sincere apologies and remorse to all the women who suffered. Many of them were from the Korean Peninsula.

Japan has been treading warily with the administration headed by President Moon Jae-in ever since discord was first voiced in the government in Seoul toward the agreement.

“What Seoul is saying is tantamount to calling the bilateral agreement ‘insufficient’ although it stated it will not seek renegotiation,” said a high-ranking Foreign Ministry official.

A senior official at the prime minister’s office indicated that, under the circumstances, it would be “impossible” for Abe to attend the Opening Ceremony of the Pyeongchang Olympics that get under way in South Korea next month.

The Japanese government is also rankled by Seoul’s decision to match the 1 billion yen that Japan provided to the Reconciliation and Healing Foundation.

The provision is aimed at allowing the foundation to continue with its aid activities without relying on the Japanese funds.

“If Seoul means to replace the money with its own funds, it is effectively scrapping the accord--and that is not acceptable,” said the senior Foreign Ministry official. “Returning the contribution is not a possibility, either.”

Japanese officials plan to seek an explanation from Seoul about how it will handle the 1 billion yen given by Japan.

Kono indicated that Japan envisages no change in its basic stance to work closely with South Korea, given the unpredictability of North Korea.

“The bilateral agreement is an essential foundation upon which the two countries will build future-oriented ties through joint cooperation in the face of North Korea’s threat,” Kono told reporters.