South Korea's top diplomat is expected to visit Japan next week before a task force announces the results of its monthslong review of a controversial deal on Japan's wartime sexual slavery of Korean women, multiple sources said Monday.

Foreign Minister Kang Kyung-wha will likely visit Japan from Dec. 19-20 to hold a bilateral meeting with her Japanese counterpart Taro Kono, according to the government sources close to the matter.

Her trip to Tokyo would be made before the task force is set to come out with its review of the overall procedure by which the deal was made in late 2015 between the two neighbors on the so-called comfort women issue.

"It still remains to be seen how the schedule for the minister's trip will be finalized but it seems that it will likely happen before the task force's review will come out," a source said.

South Korea and Japan reached in December 2015 to leave behind Tokyo's wartime sexual slavery of many Korean women, who are euphemistically called comfort women.

Under the deal, they agreed to "finally and irreversibly"

resolve the comfort women issue, while Tokyo gave an apology for its colonial-era atrocities and agreed to contribute 1 billion yen ($8.9 million) to a foundation dedicated to supporting the victims.

It, however, prompted strong criticism from civic groups and some of the victims as well, as they claim that Japan's apology is not sincere enough and that the government did not consult with them in advance.

The Moon government, which took office in May, has said that there appear to be procedural problems in reaching the deal. The task force launched after the new government's inauguration earlier said that it will finalize its review of the controversial deal within this year.

Japan is urging South Korea to faithfully carry out what was agreed upon in the deal. The Seoul government is saying that it will seek a "two-track" approach in which such historical issues will be separated from bilateral diplomatic relations.

Historians estimate that up to 200,000 women, mostly from Korea, were forced into sexual servitude during wartime. The number of surviving South Korean victims stands at 33. (Yonhap)