Seoul officials said members of the International Hydrographic Organization voted overwhelmingly against Japan's proposal to continue referring to the body of water only as the Sea of Japan, Yonhap News Agency reported. Only Japan voted for the single name, with the other 77 members either voting against it or abstaining, the South Korean news agency said.
South Korea wants global charts called the "Limits of Oceans and Seas," commonly known as S-23, to include the name East Sea along with the Sea of Japan until an agreement is reached on disputed areas.
Seoul officials said the issue would be taken up again Friday, the final day of the five-day meeting.
The naming issue -- which dates to the early 1920s when Japan registered the name sea of Japan with the international organization -- is part of a wider dispute between Japan and South Korea over a string of islets the Koreans call Dokdo and the Japanese call Takeshima. The rocky outcroppings are a lucrative fishing ground and could turn out to be a valuable source of natural gas.