The first group of about 200 United States Marines have arrived in Darwin as part of the ninth Marine Rotational Force.
Defence Minister Linda Reynolds says the deployment is the result of extensive planning and coordination between both nations to address challenges posed by COVID-19.
"Australia's alliance with the United States is our most important Defence relationship. It sends a clear signal about our commitment to the security and stability of our region," Senator Reynolds said in a statement on Tuesday.
The deployment will grow to 1200 personnel over the next eight weeks and will train through to September.
Australian Associated Press