South Korea warned Japan Wednesday not to undermine a bilateral deal on "comfort women," upset about Japan's repeated denial of the forced nature behind the wartime atrocity.

Japan should "refrain from words and deeds to damage the spirit and purpose" of the Dec. 28 agreement, the Foreign Ministry said in a statement.

Under the verbal accord, the Japanese government offered an apology for the sexual enslavement of Korean women by its troops during World War II. It also agreed to provide 1 billion yen ($8.3 million) to create a foundation for more than 40 surviving Korean victims.

The two sides announced that the decades-long dispute over the comfort women issue was resolved in a "final and irreversible" manner.

But Japan has since taken an attitude that sparks misgivings about its real intentions.

It especially continued to deny that there was coercion in recruiting Korean women for frontline comfort stations.

Leading Japan's delegation to a U.N. session in Geneva, Deputy Foreign Minister Shinsuke Sugiyama said, "In the early 1990s, when the comfort women issue became a political and diplomatic problem between Japan and the Republic of Korea, the Japanese government conducted a thorough investigation, but there was no document confirming that the Japanese government or army forced comfort women into sex servitude," he told the Committee on Elimination of Discrimination against Women under United Nations Human Rights Council.

He was reiterating Tokyo's position in a document submitted to the panel earlier.

South Korea stressed that it's an "undeniable historical fact" that Japan used coercion to recruit and mobilize those Korean women when Korea was under Japan's brutal colonial rule.

It called on Japan to show through action that it would recover the honor and dignity of the victims and heal their wounds.

The premise of the "final and irreversible" deal is that Japan faithfully implements it, the Foreign Ministry said. (Yonhap)