President Moon Jae-in said Thursday that inter-government agreements between Seoul and Tokyo did not settle issues of individual compensation to Koreans who were forced into sexual slavery and forced labor during the 1910-45 colonial rule.
Moon's statement is likely to deepen the diplomatic row between Korea and Japan, as Tokyo has repeatedly claimed that the dispute over former Korean sex slaves was resolved through a bilateral agreement reached in December 2015.
"The issues on comfort women were not discussed when the two governments signed a treaty in 1965. It's not right to say the issue of the 'comfort women' was settled through the bilateral talks," Moon said during a televised news conference at Cheong Wa Dae.
The press meeting took place to mark Moon's 100th day as president.
Moon also said agreements reached between the two governments should not violate individual rights concerning forced laborers.
Japan has claimed that the 1965 treaty, which normalized diplomatic relations, settled all legal issues resulting from its colonial rule in the form of economic aid to the then Park Chung-hee administration.
Since then, it has refused to make reparations to individuals who were exploited by Tokyo before and during World War II.
Among them were Korean workers who were forcibly taken to Japan and produced military supplies for Japanese companies such as Mitsubishi.
"The judicial precedents from the Constitutional Court and the Supreme Court show that the victims of coerced labor have civil rights to file a suit against firms including Mitsubishi," Moon said. "Our government deals with historical issues accordingly, although I want to underscore that the past issues should not be a stumbling block to future-oriented relations between Korea and Japan."
Moon brought up the issues with regard to an ongoing investigation by a task force set up under the Ministry of Foreign Affairs to uncover hidden details regarding the accord between Korea and Japan in December 2015.
The deal was aimed at resolving the issues on sex slavery "finally and irreversibly" under the Park Geun-hye government.
But many in Korea criticized the agreement for not taking into account the opinions of surviving victims, and Moon has sought to renegotiate the deal despite Japan's objections.
"Our foreign ministry will come up with policies accordingly when the review of the accord is over," he said.
Moon's remarks were in line with his promise Tuesday that he will not overlook Japan's wartime atrocities, while at the same time he put emphasis on "on forward-looking Korea-Japan relations" to bolster peace and prosperity in Northeast Asia.