President Duterte has warned of "unfriendly" treatment for foreign vessels traveling in Philippine territorial waters without permission, in a rare swipe at China's use of warships in the country's southern waters without giving local authorities a heads-up. Presidential spokesperson Salvador Panelo made the demand for transparency amid frustration by the Philippine military at multiple sightings this year of Chinese warships moving within the country's 22-kilometer territorial sea, particularly in Sibutu Passage in Tawi-Tawi province. "To avoid misunderstanding in the future, the President is putting on notice that beginning today, all foreign vessels passing out territorial waters must notify and get clearance from the proper government authority well in advance of the actual passage," Panelo said.

Aurelio, J. M. & Ramos, M. (2019, August 21). Du30: Intrusive foreign ships face 'unfriendly' PH response. Philippine Daily Inquirer, p. A6.