With the final call just a day away, uncertainties persist over how South Korea and Japan will settle their dispute over Tokyo's bid to turn a set of industrial facilities linked to wartime Korean slave labor into world heritage sites, officials said Friday.
  

Last month, the two sides appeared to have reached an agreement on the issue after Foreign Minister Yun Byung-se and his Japanese counterpart Fumio Kishida met in Tokyo on the occasion of the 50th anniversary of the normalization of bilateral ties.
  

Recent developments, however, including Japanese Deputy Foreign Minister Shinsuke Sugiyama's unannounced visit to Seoul this week, have spurred speculation of a rift in last-minute negotiations.
  

"They haven't been able to agree fully yet," a government official told Yonhap News Agency, speaking on condition of anonymity due to the sensitivity of the issue. "The Japanese have agreed with us in principle but the devil is in the details."
  

South Korea has demanded that Japan acknowledge its use of forced Korean labor at some of the early industrial sites shortlisted for the UNESCO World Heritage list. Korea was under Japanese colonial rule from 1910-45.
  

A final decision on the bid is expected to come Saturday during an ongoing meeting of the World Heritage Committee in Bonn, Germany.
  

"We agreed to settle the issue in a fairly reasonable way and made various forms of progress, but slight difficulties were raised in the final negotiations, so coordination between the sides is under way," Ju Chul-ki, the senior presidential secretary for foreign affairs, said during a parliamentary meeting.
  

Among the possible solutions is attaching an annotation on the Korean slave labor to UNESCO documents, according to diplomatic sources.
  

Tokyo, meanwhile, has proposed the two sides fine-tune Seoul's position on the candidate sites' registration before South Korea expresses its view at the committee meeting, Japan's Kyodo news agency reported Thursday.
  

"There was a broad agreement when the minister visited (Japan), so unless someone breaks that agreement, it will be resolved smoothly," said another government official, requesting anonymity.
  

The issue is expected to set the tone for the future of the two countries' ties, which have long been marred by disputes over their shared history. (Yonhap)