TAIPEI (Taiwan News) — China’s coast guard said Monday it carried out patrols in waters east of Taiwan in response to Japan and the Philippines planning maritime boundary talks in areas that China also claims.

Japan and the Philippines said last Thursday that, in an effort to promote peace and mutual trust, they would hold discussions “to delimit the maritime boundary of the exclusive economic zone and the continental shelf between the two countries, in accordance with international law.”

China’s foreign ministry on Friday said the area in question included waters east of Taiwan, which Beijing claims as its own territory. It labeled the talks “completely illegal, null and void,” Reuters reported.

China’s coast guard said it conducted the patrol in accordance with the law, but did not disclose the exact location, per Reuters. It said the move was “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.”

Taiwan’s Coast Guard Administration said in a statement that the Chinese ships were more than 92 kilometers away from Orchid Island, outside Taiwan’s restricted waters. The CGA reiterated that Taiwan and China “are not subordinate to each other” and that Taiwan’s sovereignty “must not be violated or annexed.”

The CGA pledged to continue upholding maritime security through surveillance and intelligence gathering.

Taiwan’s Ministry of Foreign Affairs criticized the patrol, saying, “Taiwan’s territorial sovereignty and rights over its surrounding waters are not subject to comment or interference by China.”

However, the ministry welcomed the talks between Japan and the Philippines. It said Taiwan was willing to explore cooperation on sharing marine resources, safeguarding maritime security in the Indo-Pacific, and promoting sustainable development.