Japanese Prime Minister Shinzo Abe tied the $8.3 million fund with the removal of the "comfort women" statue outside the Japanese Embassy in Seoul, the Kyodo news services cited the source as saying Wednesday.
Additionally, Tokyo has requested that the dispute be closed permanently with Monday’s agreement.
Public opinion in Japan is divided over the agreement. Opponents decry the failure of Japanese diplomacy, citing no joint statement following the talks, the tenfold growth of the support fund and no clear commitment from Seoul to remove the statue.
Up to 200,000 women, most of them Korean, are estimated to have been forced to work in brothels in service of Japanese soldiers in wartime.
Earlier on Thursday, the Seoul district court opened hearings in a lawsuit filed by 12 comfort women in 2013, 10 of whom remain alive and each seek $85,000 in damages.
