Lieutenant Colonel Steven Sutey, commander of this year’s annual Marine Rotational Force Darwin, says the US military is “on track” to grow its numbers in northern Australia.

This year’s rotation, made up primarily of the California-based 1st Battalion, 1st Marine Regiment, will see 1250 US Marines based in Darwin, most at Robertson Barracks, for six months.

This is the fifth and largest group to be deployed to Australia since MRF-D was announced by the US and Australian governments in 2011 to improve interoperability between the two militaries.

Lt Col Sutey, who arrived in the Top End on Saturday, said this year’s force was the third battalion-sized group to come to Darwin.

“We are on track to grow our numbers over the years to that goal of 2500,” he said.

“This year’s force brings with it four UH-1Y (Venom) helicopters – a different capability than the CH-53s we’ve bought in the past - that will allow us to do more with our live-fire exercises (such as) close support as well as assault support and aerial command and control that we haven’t been able to do in the past."