The Philippines Coast Guard has been hosting personnel from Japan and the United States in their first joint exercise that began last Thursday in waters off Manila Bay that faces the South China Sea.

The seven-day exercise involves six patrol ships. Reporters were allowed access to part of the drill on Tuesday.

The exercise simulates confronting suspicious vessels, and how to intercept a vessel overtaken by pirates.

The drills are being held after the Philippines accused China's Coast Guard of blocking or approaching dangerously close to its patrol ship in disputed waters in the South China Sea in April.

Japan, the US and the Philippines plan to expand maritime security cooperation to counter Beijing's growing assertiveness.

A Philippine coast guard official said the three countries will help each other respond to future contingencies.