A new contingent of US Marines are headed to Darwin in the eighth rotation of American troops training down under.

The ramp-up from 1700 Marines expected to arrive this year to 2500 will be the first time US troop numbers reach the full planned complement.

The Morrison government says the increased US military presence was the result of Australia's strong alliance and friendship with the US.

This year, the Marines will participate in multiple training activities with Australian troops, including a new humanitarian assistance and disaster response segment.

Aircraft deploying to Australia’s Northern Territory include 10 MV-22 Osprey tiltrotors, four AH-1Z Vipers and three UH-1Y Venom helicopters, a Marine spokesman said.

Aircraft deploying for the rotation include 10 MV-22 Osprey tiltrotors, four AH-1Z Vipers and three UH-1Y Venom helicopters, Marine spokesman 1st Lt. Colin Kennard said in an email.

The aircraft represent “the most capable Aviation Combat Element” sent to Darwin since the rotational deployments began in 2011, he said.

“These aircraft increase the training value for MRF-D activities and increase our ability to respond to contingencies within the Indo-Pacific region,” he said.

To facilitate operations for the U.S.A. helicopters, temporary airfield matting has been installed at RAAF base Darwin.

US Colonel James Schnelle is stood down from his job of commanding the largest contingent of Marines ever to rotate through the Top End after being caught drink-driving, a Darwin court hears.

Colonel James Schnelle, 48, appeared in Darwin Local Court this morning, charged with medium-range drink-driving.

The court heard he failed a random breath test on Darwin's Mitchell Street in the early hours of a Sunday morning late last month.

No conviction was recorded, but the court heard Colonel Schnelle had been stood down from his job of commanding the largest contingent of Marines ever to rotate through the Top End.

Colonel Schnelle is the highest ranking US Marine in Darwin, and is a decorated commander with three service awards.

"This is a man of very high character, he has no convictions anywhere in the world and has contributed immensely to society," Colonel Schnelle's lawyer told the court. "The US Marines are going to deal with him very harshly." His lawyer said any conviction would affect any assignments or promotions he could hope to get in future.

A US Marine charged with the violent assault of a female public servant in a car park at Enoggera has had his bail amended to allow him to return to Brisbane.

Taylor Wyatt Elwood, 20, was arrested at Enoggera Barracks in Brisbane's north-west on July 3 after allegedly dragging the woman, aged in her 60s, out of her parked car and assaulting her.

He was further charged with allegedly assaulting an off-duty police officer who intervened, and wilful damage to the woman's car.

The woman was taken to hospital by ambulance for treatment of facial injuries and later released. In July Mr Elwood was permitted by the court to relocate to Robertson Barracks in Darwin as part of the US Marine Rotational Unit.

Japan's Prime Minister Shinzo Abe will make a historic visit to Darwin this November to help cement modern day relations with Australia.

Shinzo Abe is scheduled to be welcomed to the Northern Territory by Prime Minister Scott Morrison in November, before both men fly to Port Moresby for the APEC meeting of regional leaders.

Japan's massive $34 billion INPEX gas pipeline project will be the focus of Mr Abe's visit, but closer military ties are also expected to be high on the agenda when the two leaders meet.

Mr Abe's is the first visit to Darwin by a Japanese leader since forces struck the key military port, killing more than 250 people across multiple bombings in 1942 and 1943.

Top end diplomatic tango: Japan and US compete for attention. In mid-November Australia's top end will be the stopover point for regional leaders straddling two major meetings, the East Asia Summit in Singapore and the APEC gathering in Port Moresby a few days later. The ABC can reveal that during the brief period between the two summits, United States Vice-President Mike Pence will stay in Cairns, at the same time that Mr Morrison hosts his Japanese counterpart in Darwin. Mr Pence, who met with Mr Turnbull during a visit to Sydney in 2017, is expected to fly into the APEC summit each day from northern Queensland rather than staying overnight in Port Moresby.