MANILA-The Philippines is not obliged to notify China about its resupply missions in the South China Sea, saying these operations, including the "upkeep" of a grounded navy ship are legitimate, its foreign ministry said on Thursday.

Philippine Coast Guard flyby over the South China Sea

The Department of Foreign Affairs (DFA) also called on China to remove all "illegal structures" it built within the Philippines' exclusive economic zone (EEZ), cease reclamation in those areas and be accountable for the damage the activities caused.

China has repeatedly accused the Philippines of illegally entering its waters without its permission during its missions to transport food and water to Filipino soldiers living aboard a navy ship that Manila grounded at the disputed Second Thomas Shoal. The atoll is called Ayungin by the Philippines and Renai Reef by China.

"We are being asked to give prior notification each time we conduct a resupply mission to Ayungin Shoal. We will not do so," DFA spokesperson Teresita Daza said in a statement.

China claims sovereignty over nearly the entire South China Sea, pointing to a line on its maps that cuts into the EEZs of Vietnam, the Philippines, Malaysia, Brunei and Indonesia. Taiwan, which China claims as part of its territory, has also said it does not accept Beijing's maps.

The Permanent Court of Arbitration in 2016 said the line on China's maps had no legal basis, which Beijing rejects.

US Defense Secretary Lloyd Austin reiterated his support for the arbitral ruling during a meeting with his Manila counterpart in Jakarta. Both have denounced harassments by China towards Philippine vessels conducting the resupply mission.

Since the grounding of the Sierra Madre ship at the atoll in 1999 in Manila's attempt to assert its sovereignty claim, China has repeatedly called on the Philippines to tow away the vessel, based on a supposed agreement, which Manila reiterated did not exist.

"The Philippines has not entered into any agreement abandoning its sovereign rights and jurisdiction over its EEZ and continental shelf, including in the vicinity of Ayungin Shoal," Daza said.

The Second Thomas Shoal lies 190 km (118 miles) off the Philippine island of Palawan, or well within the Manila's EEZ.

China's embassy in Manila did not immediately respond to a request for comment.