Armed and defense forces from Japan, the US, the Philippines and Australia have held a joint maritime exercise in the South China Sea. The four countries demonstrated their maritime cooperation for the first time since Donald Trump took office as US president again.

The drill took place Wednesday in waters in the Philippines' exclusive economic zone. Participating were destroyers from Japan's Maritime Self-Defense Force, the US and Australian navies and a Philippine Navy frigate. The countries aim at strengthening their interoperability.

The US Defense Department said the same day that Defense Secretary Pete Hegseth and his Philippine counterpart, Gilberto Teodoro, held their first talks by phone.

The department says they discussed reestablishing deterrence in the region by working with allies and partners. They also discussed strengthening the capabilities of the Philippine military.

China has been flexing its muscles in the South China Sea. The Philippines has been seeking to counter this by boosting military cooperation with the US and other partner countries.