South Korea and Japan began another round of talks Wednesday aimed at resolving the issue of Korean women forced into sexual servitude for Japanese soldiers during World War II.

Japanese negotiator Kimihiro Ishikane refused to speak to reporters as he walked into the Foreign Ministry building for talks with his South Korean counterpart, Lee Sang-duk.

Ishikane heads the Japanese foreign ministry's Asian and Oceanian affairs bureau.

The working-level talks -- the 10th of its kind -- came amid skepticism that the sides could not produce any breakthroughs in one of the knottiest issues between the two neighbors.

Earlier this month, President Park Geun-hye and Prime Minister Shinzo Abe agreed to accelerate the negotiations to try to resolve the issue as early as possible, without specifying a time frame.

As many as 200,000 women, mostly Koreans, were forced to serve as sex slaves in Japan's frontline brothels during the war. The victims are euphemistically called "comfort women."

The issue has gained urgency in recent years as the victims are dying off. In 2007, more than 120 South Korean victims were alive, but the number has since dropped to 47, with their average age standing at nearly 90.

Both Seoul and Tokyo view the related dispute as "the biggest obstacle" to efforts to improve their ties.

A sticking point is the divergent interpretation of a 1965 deal to normalize diplomatic relations with Seoul.

The Abe administration maintains that the legal issue was settled at that time. But South Korea has stressed that the comfort women issue was not addressed in the agreement which focused on dealing with the economic side.

The Park government is demanding a formal apology and compensation for Korean victims from Japan.    

"Our unswerving position is that (the issue) was not included in the 1965 deal between South Korea and Japan," Vice Foreign Minister Lim Sung-nam said in a radio talk show. (Yonhap)