Taiwan deployed coast guard vessels on Sunday after China launched what Beijing described as a maritime law enforcement operation in waters east of the self-ruled island, escalating tensions over a region already caught in competing territorial claims.

Taiwan’s Coast Guard Administration said it had monitored four Chinese government vessels that departed from Xiamen and moved toward waters east of Taiwan. More than five Taiwanese coast guard ships were dispatched to track the operation and “respond appropriately.”

The move came a day after Chinese state media reported that maritime authorities from Fujian and Guangdong provinces had begun a special law enforcement operation in the area.

Beijing said the action was a response to plans by Japan and the Philippines to begin formal talks on delimiting maritime boundaries between their exclusive economic zones and continental shelves.

China condemned the planned negotiations as “illegal” and asserted jurisdiction over the waters surrounding Taiwan, which Beijing claims as part of its territory.

Taiwan rejected the claim, insisting that China has no sovereign rights over waters east of the island and arguing that Taipei should be consulted on any maritime boundary discussions involving the area.

Expanding presence

The latest standoff underscores the growing strategic convergence between Japan and the Philippines, both of which have been locked in separate maritime disputes with China.

Tokyo continues to face Chinese pressure in the East China Sea, while Manila has repeatedly clashed with Chinese coast guard and naval vessels in the South China Sea.

Adding to the tension, Taiwan reported that a Chinese survey vessel had recently operated alongside a Chinese coast guard ship near Pratas Island, a Taiwan-controlled territory in the northern South China Sea also claimed by Beijing.

Taiwan described the joint deployment as the first observed instance of Chinese coast guard and survey vessels coordinating operations around the island, raising concerns that Beijing may be expanding both its legal and physical presence in contested waters across the region.