Southeast Asia’s top diplomats have opened three days of talks in the Philippine capital with an agenda topped by their most daunting security problems.

The Philippine defense chief has condemned China’s deployment of a swarm of armed coast guard forces, backed by a helicopter and a drone, closer to the Philippines' military outpost in a fiercely disputed atoll in the South China Sea.

A Chinese navy helicopter has flown within 10 feet of a Philippine patrol plane in a disputed area of the the South China Sea, highlighting Beijing's use of force in asserting its claims to the strategic waterway.