The U.S and Indonesian militaries were joined by partner nations for the first time as they began nearly two week long drills on Sumatra Island and the Riau islands in Indonesia.
The planned drills opened after China´s Defense Ministry said Tuesday night it would conduct a series of targeted military operations to 'safeguard national sovereignty' in response to U.S House Speaker Nancy Pelosi´s visit to self-governed Taiwan, which China claims as part of its territory to be annexed by force if necessary.
China has also been increasingly assertive over its claim to virtually the entire South China Sea.
Thanks to Taiwan's high levels of production of microchips, there are worries that the Chinese military could create a crisis by cutting off the island from the world's supply chain.
Pelosi is thought to be leaving Taiwan on Wednesday. The US/Indonesian drills are scheduled to run from August 1 until August 14.
In total, more than 5,000 troops from the US, Indonesia, Australia, Japan and Singapore, will participate in the drills. It will be the largest drill since the annual joint-exercise began in 2009. Around 2,000 of the participating soldiers are from the US.