Several Pacific Island nations have participated in the major military exercise Talisman Sabre for the first time as Australia seeks to bolster partnerships in the region.
The multi-national exercise has swelled to almost 32,000 defence force personnel from 13 countries.
This year's two-week exercise was the largest iteration yet, held across locations including Shoalwater Bay in Queensland.
Director of the exercise Brigadier Damian Hill said it was the first time forces from Fiji, Tonga, and Papua New Guinea had been fully integrated into the exercise.
"There's just an opportunity, there's a willingness in the region to work together," he said.
"We know that we will need to work together, exercises such as this enable us to create those personal relationships."
Other nations to step up their participation included Japan and South Korea.
Asked about the significance and scale of the exercise in the context of regional competition, Brig Hill pointed to increased cooperation on humanitarian assistance, disaster relief, and COVID-19 response and recovery efforts.
A Chinese surveillance ship was spotted by a RAAF P-8 Poseidon plane, trying to collect information about the war games.
Brig Hill said he expected Beijing to continue to "have an interest in the exercise" when it was next held in a couple of years.
Deputy Prime Minister Richard Marles will travel to Queensland on Sunday with US Secretary of Defence Lloyd Austin to visit military personnel taking part in the drills.
Tess Ikonomou - AAP