A Greens Senator in Australia says a social impact study should be done before large numbers of American troops are sent to the Northern Territory.
United States President Barack Obama announced plans during a visit to Australia last year to increase the US military presence in Darwin.
About 2000 defence personnel at a time are expected to be stationed in the Northern Territory on a rotational basis.
The ABC reports Senator Scott Ludlam has told an estimates committee there have been social problems in places like Okinawa in Japan, where US marines are stationed.
