Taiwan’s coast guard said Sunday it has deployed vessels “to respond appropriately” to a Chinese operation in waters east of the island democracy, which it said “violates international law.”

The move comes after Chinese state media reported Saturday that the “law enforcement operation” was in response to talks between Japan and the Philippines to draw a boundary in the affected waters.

China, which asserts Taiwan is part of its territory, called the talks “illegal” and has claimed exclusive control over the waters.