The U.S. Government has decided to base a USMC (United States Marine Corps) Task Force at Robertson Barracks (Australian Army) base at Darwin, Northern Territories for 6 month rotations, until at full strength ie, 2016. It is based in the East Timor Sea, and near the Indian Ocean Region etc.
More on this topic.
(Similar to Canadian Ranger operating in Canadian High Arctic, and Coastal region area's.)
These links are for interest sake etc.