Foreign Minister Taro Kono on Monday urged South Korea to make good on promises made in bilateral pacts related to the issues of wartime labor and "comfort women," as diplomatic relations between the neighbors become increasingly frosty.

The term comfort women is a euphemism used to refer to women who provided sex, including those who did so against their will, for Japanese troops before and during World War II.

The issue of wartime labor flared up again as a source of diplomatic friction late last year, when South Korea's top court ruled in favor of South Korean plaintiffs seeking compensation for labor they claimed they were forced into carrying out during Japan's 1910-1945 colonial rule of the Korean Peninsula.