TOKYO, Jan. 10 (Xinhua) -- Japan lodged a protest with South Korea on Wednesday over President Moon Jae-in's remarks suggesting that Japan untie an "erroneous knot" over the "comfort women" issue by sincerely apologizing to the victims.

Kenji Kanasugi, director general of the Japanese Foreign Ministry's Asian and Oceanian Affairs Bureau, told a senior official from the South Korean Embassy in Tokyo that Moon's remarks are "unacceptable," Kyodo News here quoted a ministry source as saying Wednesday.

Kanasugi's protest followed Moon being quoted by local media as saying during a New Year's press conference that "Japan should accept the truth, apologize with a sincere heart and take the 'comfort women' issue as a lesson and work with the international community in such a way that something similar could not occur again."

South Korean Foreign Minister Kang Kyung-wha intimated a day earlier that Tokyo should do more to atone for its past wartime crimes involving "comfort women," although maintained that Seoul would not seek to renegotiate a bilateral deal on the issue made two years ago.

Moon said on Wednesday that while it is "undeniable" that the deal is an official bilateral agreement, the "erroneous knot" with Japan over the "comfort women" issue must be untied by Tokyo apologizing to the victims.

Japan's Chief Cabinet Secretary Yoshihide Suga also rejected South Korea's requests for Japan to do more than it had agreed to in the 2015 deal.

Suga said both countries have already committed to steadily implementing the deal and that both sides agreed the deal would settle the issue "finally and irreversibly."

A day earlier, Japan's Foreign Minister Taro Kono said Japan cannot accept South Korea's new policy position on a deal struck in 2015 between the two countries over the "comfort women" issue.

The steady implementation of this agreement is both countries' duty to the international community, Kono said following South Korea announcing its policy position.

The Japanese foreign minister said Japan would like further clarification as to what Seoul means by "matching Japan's contribution" and how it plans to use the funds.

Seoul, while maintaining it will not seek to renegotiate the deal, said it will plan to match the 1 billion yen (8.93 million U.S. dollars) paid by the Japanese government under the deal, with South Korea's Foreign Minister Kang Kyung-wha saying that it will decide how to use Japan's contribution.

Under a landmark bilateral deal reached two years ago, both countries agreed that the "comfort women" issue that had led to ties between both countries becoming significantly strained, would be "finally and irreversibly" resolved.

South Korean President Moon, who took office in May, and his administration, however, have said they are revisiting the process under which the accord was made under the previous government, noting that the pact does not reflect the will of the majority of South Korean people.

The so-called "comfort women" issue involved soldiers from the Imperial Japanese Army during World War II, forcibly coercing and even kidnapping girls and women, and forcing them to work as sex slaves, servicing Japanese soldiers at military brothels during the war.

Many of the women forced into sex slavery by the Japanese aggressors came from the Korean Peninsula as well as from other parts of Asia, including China.

Euphemistically, these sex slaves have come to be known collectively as "comfort women."

Statues erected to pay honor to these "comfort women" such as the one installed outside the Japanese consulate in South Korea's Busan, draw the ire of the Japanese government, the right-wing forces of which have been trying ardently to whitewash its wartime atrocities.

Despite the possibility of ties between the two countries becoming strained once more, Suga said Tuesday that Tokyo is "not thinking of moving even a millimeter on the deal."

The South Korean side, however, believes that prior to the deal being made with Japan, those who served as "comfort women" were not sufficiently consulted and their feelings not fully taken into account.

"A sincere apology from Japan to the surviving 'comfort women' and for those who have already passed, would go along way towards restoring the women's honor and dignity and restoring political and social ties between both countries," a representative of a Japan-based think tank said on Wednesday.