South Korean President Moon Jae-in said in an interview published Tuesday that Japan must "take legal responsibility for its actions" and "make an official apology" in order to resolve a controversy over a deal to tackle the lingering issue of "comfort women."

Moon's remarks in an interview with The Washington Post were his strongest to date regarding a 2015 agreement struck by his predecessor on the women who were forced to provide sex at Japanese military brothels before and during World War II.

"The core to resolving the issue is for Japan to take legal responsibility for its actions and to make an official (government) apology," he said.