Osaka Mayor Toru Hashimoto said Thursday that he has sent a letter to the board of supervisors of sister-city San Francisco to request that it retract a resolution condemning his remarks seeking to justify Japan's wartime system of military brothels.

Hashimoto, who doubles as co-leader of Nippon Ishin no Kai (Japan Restoration Party), drew international scorn over remarks he made in May that the wartime brothels, and their "comfort women," were "necessary" for Japanese soldiers.

The board unanimously adopted the resolution on June 18, stating it "strongly condemns the attitude and statements" of Hashimoto "justifying the state-sponsored 'comfort women' system, which forced hundreds of thousands of Asian women into sexual servitude for the Japanese military."