Japan is considering attaching an annotation to UNESCO documents to acknowledge that Korean slave labor took place at some of its candidate sites for the World Heritage list, according to diplomatic sources Wednesday.

South Korea has taken issue with Tokyo's bid to list a package of Meiji Era industrial facilities as UNESCO World Heritage sites as they include seven facilities where nearly 60,000 Koreans were forced to work during the 1940s when Korea was under Japanese colonial rule.

Talks have been under way to resolve the dispute before member nations of the World Heritage Committee gather in Bonn, Germany next week to decide on the bid.

In a series of high-level meetings this week, the two sides reached a tentative agreement to attach an annotation on the Korean slave labor to UNESCO documents listing the facilities as World Heritage sites, the sources said.

Differences, however, remain over South Korea's stance that Japan acknowledge the laborers were taken by force, they said.

Japanese media have reported that the Japanese government is also considering other measures, such as revealing the slave labor history on signs at the sites, on the websites of local governments with jurisdiction over them and on pamphlets for visitors. (Yonhap)