The presence of more than 1500 US marines in Darwin should be welcomed and is a "really positive engagement", Defence Minister Marise Payne says.
Senator Payne made the comments after viewing a computer simulation exercise involving Australian and US forces in which bombs explode in Darwin's Cullen Bay and the troops respond during a visit to Robertson Barracks in the Top End.
The simulator can be used for mission rehearsal exercises for any scenario before going to an "operational or live firing environment", Australian Army's Major Max Williams told the minister.
The number of US marines in Darwin has been gradually increasing to 2500 since first being stationed in 2012.
There are 15 different joint training exercises planned over the next six months.
Opponents such as the Chinese government say Australia should not be welcoming foreign troops and siding with the US to contain China.
Others support the idea that the forces will contain China and its aggressive military build-up in the South China Sea including the construction of artificial island bases.
"Australia has been very clear about its position ... for examples we have encouraged all claimants, it is important to remember that there are multiple claimants, to resolve those issues peacefully in accordance with international law and according to a rule-based global order," the minister told reporters on Tuesday.
The meeting comes at a time of increased tension between China and both the US and Australia.
The US withdrew an invitation to China to attend the Rim of the Pacific naval exercises this year and US Secretary of Defence James Mattis warned Beijing during a speech in Singapore last weekend of consequences over its aggression in the South China Sea.
Foreign Minister Julie Bishop said this week the government wanted to be the "partner of choice" for Pacific island nations, in what was seen as a message to China over its increasing ties in the region.
Senator Payne also viewed Australian and US troops conducting artillery exercises and met with US Lieutenant General David Berger and commanding general of marine forces in the Pacific and Australian Major General Rick Burr.
"This year, just looking in front of us, it is a pretty phenomenal example of what an alliance really actually means. I am grateful for it, it is tremendous seeing the training going on this morning ," Gen Berger told reporters.
