MANILA (Reuters) – The Philippines has deployed a warship off the waters of Palawan island facing the South China Sea to “protect its maritime interests”, a senior navy official said, in a move that may irk China.

Amid simmering tensions in the disputed waterway, Commodore Edward Ike De Sagon said the ship’s presence in Palawan “will serve as a reminder to all who would dare challenge our sovereignty that we stand ready and vigilant.”

It will also “bolster efforts of safeguarding the maritime domain and interests in the country’s western frontier,” De Sagon added in a written statement dated Tuesday but sent on Wednesday.

The deployment of patrol corvette BRP Emilio Jacinto or the PS35 came days after the Philippines and the United States conducted joint maritime exercises in the South China Sea, where Manila and Beijing have traded blame over a spate of run-ins over territory.

Palawan is also home to one of four additional bases that the United States military was given access to last year under the Philippines’ Enhanced Defence Cooperation Agreement (EDCA) with its treaty ally. The province has rich fishing grounds and pristine beaches that are popular with tourists.

China claims sovereignty over almost the entire South China Sea, a conduit for more than $3 trillion of commercial shipping annually, including parts of the exclusive economic zones of the Philippines, Vietnam, Indonesia, Malaysia and Brunei.

In 2016, the Permanent Court of Arbitration in the Hague said China’s claims had no legal basis, a decision Beijing has rejected.

(Reporting by Mikhail Flores; editing by Philippa Fletcher)