The announcement by Japan's Education Ministry that its new teaching manuals for junior and senior high schools will describe the islands as "integral parts of Japanese territory" drew protests from China and South Korea, Kyodo News reported.
"It is natural for the state to teach properly about [Japanese] territory," Japanese Education Minister Hakubun Shimomura told a news conference Tuesday. "With the cooperation of our Foreign Ministry, we will explain the country's position to our neighbors."
The Senkaku Islands in the East China, which Japan controls, have become a subject of bitter territorial dispute with China, which calls them Diaoyu.
South Korea similarly claims the Takeshima islets in the Sea of Japan, which it controls. Seoul calls them the Dokdo islets.
Chinese Foreign Ministry spokeswoman Hua Chunying expressed "grave concern" over the Japanese Education Ministry action.
South Koran Foreign Affairs Ministry, in a protest, urged Japan to immediately retract its revision, saying Japan's claims over Dokdo are groundless as they have always belonged to South Korea.
Kyodo said the revised manuals are not legally binding, although as teaching guidelines, they have much impact in classrooms.