The Philippines, US, and Japan Coastguards have begun their first joint drills in the South China Sea, which is a highly disputed region.

The drills will be held near the mouth of Manila Bay and will focus on a range of maritime activities, including law enforcement and search and rescue operations.

The week-long exercises are aimed at strengthening cooperation between the three countries and countering China's increasing assertiveness in the region.

The South China Sea is a vital shipping lane and is rich in natural resources, and China claims almost complete sovereignty over it.

The United States and Japan have been actively seeking to strengthen security alliances in the Asia-Pacific region, and the drills are seen as a significant step towards that goal.

The three countries have been discussing a proposed defense pact that would allow them to deploy troops on each other's territory for training and other operations.

The Philippines and Japan are already partners in a number of maritime security initiatives, and the US has been a key supplier of vessels to the Philippine Coastguard and Navy.

The joint drills are expected to enhance the capabilities of the three countries to respond to maritime threats and emergencies.