South Korea has demanded that Japan correct its updated history textbooks to clearly state that Korean women were forced into sexual slavery for Japanese troops during World War II, a Seoul official said Wednesday.

Last week, Tokyo approved a set of updated high school textbooks that claimed the women were "mobilized" or "sent" to work at front-line brothels during the war. Before the revisions, the textbooks said the victims were "taken" or "dragged" away.

On Tuesday, the two sides held working-level talks in Tokyo to discuss the implementation of last year's agreement to settle their dispute over Japan's wartime sexual slavery.

"We delivered our clear position by expressing our concern and demanding a correction," the official with knowledge of the talks said on condition of anonymity.

Under the landmark deal, Tokyo apologized and acknowledged responsibility for the crime and offered to pay 1 billion yen

($8.9 million) into a foundation to be set up by Seoul to support the victims who are euphemistically called "comfort women."

The official admitted that the establishment of the foundation has been delayed due to ongoing talks between relevant government departments and experts.

"We should proceed quickly but there's no need to rush," he said, adding that it's hard to provide an exact time frame.

Historians estimate that up to 200,000 women, mostly from Korea, were forced into sexual slavery for Japanese soldiers during the war. The Korean Peninsula was under Japanese colonial rule from 1910-45.

Tuesday's talks also touched upon the two countries' cooperation in the wake of North Korea's nuclear and missile threats, but there was no discussion of a military intelligence pact Japan has been eager to forge with the South, the official said. (Yonhap)