China's Coast Guard on Monday said it had conducted "law enforcement" patrols in waters east of Taiwan in response to Japan and the Philippines' plans to launch maritime border delimitation talks, which overlap with areas claimed by China.
Taiwan condemned the move, but said it spotted only two Chinese ships to its southeast which did not enter restricted waters.
Japan and the Philippines said last week they would begin formal talks on delimiting the maritime boundary of the exclusive economic zone and the continental shelf between the two countries "in accordance with international law."
Delimitation involves the legal and cartographic process of defining a boundary between two regions or countries.
While they did not give details, China's foreign ministry on Friday said that area covered waters east of Taiwan, which Beijing views as its own territory, adding that such talks are "completely illegal, null and void."
In a statement, China's Coast Guard said a flotilla had carried out the patrol in accordance with the law to the east of Taiwan, though it did not specify where exactly.
"This is a necessary action taken in response to Japan and the Philippines unilaterally announcing the initiation of maritime boundary delimitation negotiations in the waters east of China's Taiwan island," it said.
"We urge Japan and the Philippines to immediately cease all illegal actions that infringe upon China's sovereign rights and interests."
Taiwan's Coast Guard said it monitored with its own ship two Chinese vessels operating southeast of its Orchid Island in the Pacific Ocean and condemned China for claiming to carry out "law enforcement activities."
"The sovereignty of the Republic of China must not be infringed upon," it said in a statement, using Taiwan's formal name. "We are firmly committed to defending national sovereignty and ensuring the security of our waters."
The Philippine and Japanese embassies in Beijing did not immediately respond to requests for comment.
TAIWAN ANGERED
Late Sunday, Taiwan's foreign ministry denounced China's comments.
"China has no right to interfere in Taiwan's territorial sovereignty and sovereign rights over its relevant maritime areas," it said.
Taiwan reports that Chinese warships and warplanes operate around the island almost daily, sometimes joined by Chinese Coast Guard ships.
Last month, a Chinese coast guard ship approached close to the Taiwan-controlled Pratas Islands at the top end of the South China Sea, but left after a stand-off with Taiwan's coast guard.
Speaking to reporters in parliament on Monday, Taiwan Defense Minister Wellington Koo said while the Coast Guard had the primary role around the Pratas, the military had a role to play by helping Taiwan's Coast Guard.
"The navy will provide the necessary assistance in accordance with our joint cooperative protocols," he added without elaborating.
China claims Taiwan and almost the entire South China Sea via a "nine-dash line" on its maps that cuts into the exclusive economic zones of the Philippines, Brunei, Malaysia, Vietnam and Indonesia. Taiwan's government rejects Beijing's claim.
