Metro Manila (CNN Philippines, November 15) — The United States and other countries should accept the "reality" that Beijing "is already in possession" of some disputed areas in the South China Sea to avoid tension in the region, President Rodrigo Duterte said Thursday.

In a chance interview with reporters before the Association of the Southeast Asian Nations (ASEAN)-U.S. Summit in Singapore, Duterte urged countries to stop provoking China with military activities.

"China is there. That's the reality. And America and everybody should realize that they are there. So if you just keep on creating little friction, one day a bad miscalculation can turn things - Murphy's Law. If anything can go wrong, it will go wrong," he warned.

READ: No mention of Chinese weather stations in ASEAN summit, DFA chief says

"I said China is already in possession. It's now in their hands. So why do you have to create frictions - strong military activity that will prompt a response from China?," he added.

China claims virtually the entire South China Sea, where ASEAN members the Philippines, Vietnam, Malaysia and Brunei have overlapping claims, along with Taiwan. Although the U.S. is not a claimant country, it conducts freedom-of-navigation operations in international waters around the disputed area and calls out China's alleged militarization in the region.

In a press briefing later that day, Foreign Affairs Secretary Teodoro "Teddy Boy" Locsin Jr. clarified that the President is not giving up the country's sovereign rights in the West Philippine Sea, or areas of the South China Sea that lie within the country's 200-mile exclusive economic zone.

"I have repeatedly said not an inch nor an iota of sovereignty [will be given up]," Locsin said.

He added that the President's call against the conduct of military drills in the contested waters may be "a matter of courtesy."

"You can do, you can postpone those things if there are pending visits," Locsin said.

Chinese President Xi Jinping is visiting the Philippines on November 20-21.

Duterte earlier assured China that the Philippines would not participate in reported plans of the U.S. to conduct military drills in the South China Sea. This was after Chinese Ambassador to the Philippines Zhao Jianhua warned that the U.S. military drills could mar Xi's upcoming visit. The U.S., meanwhile, denied plans to "show force" through freedom-of-navigation operations.

Duterte admitted that rising tension between China and the U.S. worries him. On Thursday, he said a war in the disputed waters would put the Philippines in danger.

"I do not mind everybody going to war except that the Philippines is just beside those islands and if there's a shooting there, my country will be the first to suffer. That is my only national interest there. Nothing else," he explained.

The President said he would "try [his] best" to lead ASEAN and China into signing a Code of Conduct (COC) defining what states can and cannot do in the contested waters, within the Philippines' term as country coordinator for relations between the region and Beijing. The Philippines' term ends in 2021, a year before Duterte is supposed to step down as president.

In a joint statement he read on Wednesday, Duterte said they want to come up with one negotiating draft for a COC by 2019. This draft would serve as basis for future negotiations for what ASEAN hopes would be a legally-binding COC.

READ: ASEAN, China eye completion of draft South China Sea code by 2019