President Moon Jae-in ordered disciplinary action against three government-affiliated agencies Monday for their description of the waters between Korea and Japan as the Sea of Japan, not the East Sea.

The East Sea is South Korea's official name for the waters, and the country is campaigning hard to publicize that name internationally.

But the three organizations, under the wing of the Ministry of Agriculture, Food and Rural Affairs, were found to have used the name, the Sea of Japan, on their Korean or English websites. They are Korea Forestry Promotion Institute, National Plant Quarantine Service and Agricultural Policy Insurance & Finance Service.

They also called Dokdo, a set of rocky islets in the East Sea, "Liancourt Rocks." The naming of the Seoul-controlled islets is a highly sensitive and important issue for South Koreans, as Japan claims the sovereignty over them.

"President Moon issued a grave warning against the institutions and the audit office of the related ministry will take (disciplinary) steps after a probe," Cheong Wa Dae spokesperson Ko Min-jung said at a press briefing. (Yonhap)