(Business World) THE PHILIPPINES won’t end patrols in the South China Sea, President Rodrigo R. Duterte said on Wednesday night, adding that the country’s sovereignty is nonnegotiable.

Tensions over the sea, which China claims almost entirely, have spiked as Beijing refuses to withdraw vessels from Philippine waters and Manila boosts sea patrols. Mr. Duterte is under growing domestic pressure to take a harder stance, but has been reluctant to confront China over the issue.

“I read China said we should leave,” the tough-talking leader said in a televised speech. “I now say: Do not leave. Period,” Mr. Duterte told Philippine ships that held drills in the disputed waterway.

Mr. Duterte said Philippine sovereignty over the disputed waterway is nonnegotiable even if it owes China a “debt of gratitude.”

“There are things which are not really subject to a compromise,” the President said. “I hope they will understand, but I have the interest of my country also to protect.”

China’s Foreign Ministry earlier demanded that Manila stop its sea drills in the South China Sea.

Mr. Duterte said the Philippines would not go to war with China over the South China Sea, citing the country’s long-standing friendship with its neighbor.

“We do not want war with China. China is a good friend,” he said in a televised speech, citing Beijing’s donation of coronavirus vaccines.

“So China — let it be known — is a good friend and we do not want trouble with them, especially a war,” Mr. Duterte said.

China has donated at least a million doses of CoronaVac to the Philippines.

Mr. Duterte blamed retired Supreme Court Justice Antonio T. Carpio and former Foreign Affairs Secretary Albert F. Del Rosario for China’s island-building activities in the South China Sea.

He said both had failed to stop Chinese incursions in the area under the administration of his predecessor Benigno S.C. Aquino III.

“I have one question for Carpio and Albert: If you are bright, why did we lose the West Philippine Sea?” Mr. Duterte said in Filipino, referring to areas of the sea within the country’s exclusive economic zone.

He said China’s occupation of certain features in the water happened during their time.

Mr. Carpio and Mr. Del Rosario led the country’s legal fight against China’s claims in the area. An international tribunal in 2016 favored the Philippines and rejected China’s claim to more than 80% of the sea based on a 1940s map.

Mr. Duterte insisted that invoking the legal victory, which he said was nothing but “paper,” constitutes going to war with China.

Mr. Carpio and Mr. Del Rosario and other maritime experts have said the Philippines does not need to go to war to defend its territories.