Two Chinese coast guard ships were spotted sailing off the Japan-controlled Senkaku Islands in the East China Sea over the weekend, according to local media outlets, citing Japanese coast guard officials.
Japan also lodged a protest against Beijing's "unilateral development activities" in the East China Sea on June 17, after its navy detected that China was laying the groundwork for a new structure in the disputed waters.
“It is extremely regrettable that the Chinese side is proceeding with unilateral development activities, albeit on the west side of the Japan–China intermediate line, in a situation where the boundaries have not yet been defined,” the statement reads.
The Philippines lodged a diplomatic protest against China on June 9 over the “illegal” presence of over 100 Chinese vessels “in and around” Whitsun Reef, which Manila refers to as Julian Felipe Reef, in April.
“These actions are part of a broader trend of [the People's Republic of China] provocations against South China Sea claimants and other states lawfully operating in the region,” the Philippines State Department stated.
China has built up its military presence in the South China Sea and made numerous incursions into the East China Sea, where the Senkaku Islands are located.
Japan has mostly controlled the Senkaku Islands since 1895, but Beijing began asserting its right over the islands in the 1970s and called them the Diaoyu Islands.
JMSDF Vice Adm. Hideki Yuasa said the mission aims to promote maritime order in the Indo-Pacific region, which he said has "rapidly [become] more complex and unstable.”