Foreign Minister Toshimitsu Motegi made a protest to his South Korean counterpart Kang Kyung Wha on Saturday over a court ruling in Seoul that ordered the Japanese government to pay damages to former "comfort women" in Japan's military brothels before and during World War II.
In telephone talks, Motegi, who is in Brazil, told Kang that Japan does not accept the ruling, handed down Friday, saying that it violates international law, according to the Japanese Foreign Ministry.
Motegi urged South Korea to "immediately take appropriate measures to correct the violation of international law," the ministry said.
Tokyo has said compensation issues related to comfort women were settled by a 1965 agreement between the two countries.
Motegi said the ruling also violates a bilateral accord struck in 2015 to "finally and irreversibly" resolve the comfort women issue, a longtime source of tensions between the Asian neighbors.
Japanese Prime Minister Yoshihide Suga said Friday the ruling is "utterly unacceptable."
The protest came after the Seoul Central District Court awarded 12 former comfort women 100 million won ($92,000) each as demanded, further worsening bilateral ties that have already sunk to a historic low over trade and wartime labor issues.