TOKYO — Seeking to quell an uproar over his recent comments suggesting that sexual slavery was a necessary evil in Japan’s imperial past, a populist party leader said Monday that he had not meant to justify wartime brothels or deny the women’s suffering at the hands of Japanese soldiers.

But the politician, Toru Hashimoto, who is a co-leader of the opposition Japan Restoration Association and the mayor of Osaka, Japan’s third-largest city, also argued that Japan was being unfairly singled out for its use of so-called comfort women, and that other nations needed to examine the mistreatment of women by their own militaries before pointing the finger at Tokyo.

“We must express our deep remorse at the violation of the human rights of these women by Japanese soldiers in the past, and make our apology to the women,” Mr. Hashimoto said, speaking to journalists at the Foreign Correspondents’ Club of Japan. But, he added, “it is not a fair attitude to blame only Japan, as if the violation of human rights of women by soldiers were a problem unique to Japanese soldiers.”...