The "Immediate Combat Readiness Exercise" underway until Friday is part of "annual planned joint operations training", the Ministry of National Defense (MND) said in a statement Sunday.

Taiwan's military regularly holds drills to prepare for a potential attack from China, which claims Taiwan is part of its territory and has threatened to use force to bring the island under its control.

The exercise aims to "train units at all levels during the combat readiness deployment phase, familiarising them with combat practices and the battlefield environment, and strengthening their ability to quickly transition between peacetime and wartime operations," the MND said.

Taiwan has spent many billions of dollars upgrading its military in the past decade, but is under intense US pressure to do more to protect itself against the growing threat from China.