The United States, Japan, Australia and the Philippines have started joint naval drills in the South China Sea, in a coordinated display of military readiness as tensions rise over Taiwan and disputed maritime areas.

According to Reuters, the exercises began on Friday and are aimed at strengthening interoperability among the four allies while signaling opposition to attempts to alter the status quo by force. The drills come at a time of heightened concern over China’s military pressure in the region.

The South China Sea remains one of Asia’s most volatile flashpoints, with overlapping territorial claims and frequent confrontations at sea. The latest exercises are likely to draw close attention from Beijing, which has repeatedly condemned foreign military activity in waters it claims as its own.

The maneuvers underscore the continuing push by Washington and its partners to reinforce deterrence in the Indo-Pacific, while also reflecting the growing risk that rival military exercises and patrols could deepen regional instability.