The Philippine president says the country's aircraft will continue to fly their usual routes over disputed reefs in the South China Sea, defying China's challenges to its planes and those of the United States.

President Benigno Aquino III told reporters Monday that there is no declared air defense identification zone over the area and Philippine air patrols will still fly routes based on international law.

He said he could not reveal details about arrangements being made by Manila with its military ally, the U.S., to address the problem.

China said Thursday that it is entitled to keep watch over airspace and seas surrounding artificial islands it created in the disputed waters of the South China Sea, following an exchange in which its navy warned off a U.S. surveillance plane.