 South Korea wants the name "East Sea" to be used, either instead of or in addition to "Sea of Japan;" while North Korea prefers the name "East Sea of Korea".The primary issue in the dispute revolves around a disagreement about when the name "Sea of Japan" became the international standard.Japan claims the term has been the international standard since at least the early 19th century, while the Koreas claim that the term "Sea of Japan" arose later while Korea was under Japanese rule, and before that occupation, other names such as "Sea of Korea" or "East Sea" were used in English.