SINGAPORE—National security adviser John Bolton said the U.S. would oppose any agreements between China and other claimants to the South China Sea that limit free passage to international shipping, and that American naval vessels would continue to sail through those waters.
Mr. Bolton’s remarks served as a warning to Southeast Asian leaders, who are preparing for a regional summit in Singapore this week, and particularly for the Philippines, which is now in talks with Beijing about jointly exploring natural resources in the contested area.
In meetings to develop a code of conduct this year for the South China Sea, China has tried to secure a veto over Southeast Asian nations hosting military exercises with other countries in the disputed waters.