"The Senkaku Islands are Japanese indigenous territory. The intervention in the territorial waters violates Japan’s sovereignty and is completely unacceptable," the ministry said, as quoted by the NHK broadcaster.
The Asia-Pacific region faces several territorial disputes in South China and East China seas, involving China, Japan, Vietnam and the Philippines. The Senkaku Islands have long been a stumbling block for Japan and China. The former claims it has possessed the islands since 1895, however, Beijing recalls that the Japanese maps made in 1783 and 1785 pictured the islands as belonging to China. After World War II the islands were controlled by the United States which returned them to Japan in 1972. Taiwan and mainland China still believe that Tokyo keeps control over the islands illegally. In turn, Japan sees China and Taiwan as seeking the right to possess the islands to access their marine minerals discovered in 1970s.