Australia and the United Sates are expected to announce that US marines will be based permanently in northern Australia soon.
The announcement is expected during a visit next week by US President Barack Obama.
It is expected Mr Obama will announce the United States will begin rotating Marines through a base in Darwin, with a new permanent presence on Australian soil.
The two countries have been working together for a year on ways to boost military co-operation.
The ABC reports they want to bring in more American troops into strategic areas including Darwin, as well as increase the number of joint exercises and the amount of training.
Defence Minister Stephen Smith has called it the biggest operational addition to their alliance since the 1980s.
Foreign Minister Kevin Rudd is refusing to give any details, saying any announcements were for the president and Prime Minister Julia Gillard to make.