A major redrawing of the map of the South China Sea began when Xi Jinping came to power in 2012. In the subsequent three years China built seven new bases in the Spratly Islands, three of them with large airfields,

A Philippine Coast Guard ship is seen surrounded by Chinese maritime militia vessels and a Chinese Coast Guard ship during a resupply mission for Filipino troops stationed at a grounded warship in the South China Sea,

Vietnam and the Philippines are both at odds with China over its sweeping territorial claims and growing military presence in the South China Sea. The announcement comes amid high tensions between the Philippines and China over their territorial dispute in the South China Sea.

The unprecedented surge follows a series of stand-offs and reclamation concerns at Sabina Shoal, the latest South China Sea flashpoint.