Japan is likely to issue an entry visa to former Taiwan President Lee Teng-hui if he agrees to a condition set by Tokyo that the visit be solely for medical treatment, government sources said Thursday.

Japanese officials have started negotiating the matter with Lee's representatives via the Interchange Association's office in Taipei, Japan's unofficial mission in Taiwan, the sources said.

However, a source close to Lee in Taipei told reporters Thursday evening that the Japanese side is demanding that the former president sign a written pledge regarding the conditions of the visit, which Lee was refusing.