OSAKA — Osaka formally decided Dec. 13 to end its 60-year sister-city ties with San Francisco, in protest against its sanctioning of a statue symbolizing women forced into wartime brothels for the Japanese military, the Osaka mayor said.

The acceptance of the so-called “comfort women” statue “fundamentally destroyed the relationship of trust. It cannot be helped but to dissolve the sister-city ties,” Osaka Mayor Hirofumi Yoshimura told reporters.

Yoshimura revealed his intention to cut the sister-city ties last month after San Francisco Mayor Edwin Lee signed a document authorizing the statue.

Because of Lee’s death Dec. 12 from a heart attack, Yoshimura said notification of the dissolution of ties will be made only after the new mayor of San Francisco takes office, expected in June next year at the earliest.

“It is not fair to make an important notification when its mayor is absent,” Yoshimura said, while offering condolences for Lee.

The statue — of three Chinese, Korean and Filipino girls standing hand in hand — was set up near San Francisco’s Chinatown area in September by a local private organization affiliated with Chinese and South Koreans.

Yoshimura had repeatedly urged Lee not to accept the statue, saying the inscription it bore repeated uncertain claims about the extent of the Japanese military’s involvement in the brothels and the extent of the damage inflicted.

Osaka and San Francisco formed the sister-city ties in 1957, leading to high-school student exchanges and other programs.