Japan and Australia have recently agreed to launch joint research on the future development of underwater drones, as the countries step up defense cooperation amid China's maritime assertiveness in the Indo-Pacific region.

It is the first specific project the U.S. allies will work on since they signed a deal last June to simplify procedures for joint technical studies on defense equipment, according to the two governments.

The project is intended to contribute to future interoperability of unmanned underwater vehicles between the two nations, the Defense Ministry said in a press release issued late last month upon the signing, referring to the capabilities that could potentially be used for detecting mines and other missions.