South Korean President Moon Jae-in delivers a speech at the National Assembly in Seoul, South Korea June 12, 2017. REUTERS/Ahn Young-joon/Pool

SEOUL (Reuters) - South Korea’s President Moon Jae-in said on Monday bilateral ties with Japan are being held back by historical issues, his office said, in an apparent reference to Korean women forced to work in Japan’s wartime brothels.

Moon, in a meeting with Toshihiro Nikai, secretary general of Japan’s ruling Liberal Democratic Party, said historical issues would take time to resolve and he asked Japan for cooperation and understanding, the presidential office said in a media briefing.