South Korea on Friday urged Japan to resolve outstanding dispute over Korean women forced into sexual slavery under Japan's 1910-45 colonial rule.

During the meeting in Seoul with his Japanese counterpart Kenichiro Sasae, first vice foreign minister Ahn Ho-young called for measures that can "fundamentally" resolve the issue of compensating Korean wartime sex slaves, also known as "comfort women".

Japan needs "genuine courage and wisdom" to look squarely at its past and forge forward-looking relations with South Korea, Ahn said, according to the foreign ministry here.

Sasae said Japan is mulling ways to address the issue on humanitarian grounds.

Seoul's repeated calls for talks with Tokyo on the compensation issue have been rebuked, as the former colonizer claims the 1965 treaty that normalized their bilateral ties had settled all legal issues concerning the comfort women.

Officials here counter that the issue is a humanitarian one left unaddressed by the treaty.

South Korea's insistence on the issue came after the Constitutional Court here ruled last year the apparent inaction by the government on the issue "unconstitutional".

Some 100,000 to 200,000 Asian women, mostly Koreans, were forced to provide sexual service to the Imperial Japanese Army during the World War II.