Japan has lodged a protest with China over an unapproved maritime survey around Okinotori Island, a remote atoll in the western Pacific that Tokyo claims as a base point for its exclusive economic zone in the area, a government source has said.
The Japan Coast Guard detected a Chinese research ship navigating in waters near the tiny island on Dec. 18 last year. The Chinese vessel told Japan's maritime safety agency that it was "conducting ocean research on the high seas."
Okinotori Island, located midway between Taiwan and Guam, is Japan's southernmost territorial point and is located about 1,700 km south of central Tokyo. China, while recognizing Okinotori as Japanese territory, argues that it is a "rock" and not a base point for Japan's EEZ.
"The Chinese oceanographic research ship Xiangyanghong 1 recently conducted marine scientific and research activities in waters near Okinotori in accordance with the law," Chinese Foreign Ministry spokesman Lu Kang told reporters Wednesday.
"Okinotori reef does not meet the basic requirements to be recognized as an island," Lu said. "The Japanese side unilaterally calls it an island and claims the so-called EEZ and continental shelf, but the Chinese side has never acknowledged that."
A Chinese ship was also spotted carrying out research activities in waters near Okinotori Island in March 2016.