The United States military is preparing to spend more than a quarter of a billion dollars on naval construction in the Northern Territory, in a move that could raise tensions with China.

the Defence Department says it is still too early to comment on what the US military may have planned in the Northern Territory.

"The referenced document is the Senate version of the National Defense Authorization Act, which authorises (but does not appropriate) Defence initiatives," the Department said in a statement.

"It is still progressing through the US Congress and must be reconciled with the House version before it is finalised. It is not yet approved.

"We expect the US Department of Defense will provide details of the funding in accordance with its processes and timelines following consideration and approval within the United States Government."

The draft US legislation also outlines several other proposed spending projects in the Northern Territory including $US50 million for a "new airport parking apron for the Navy", and $US70.6 million for the Air Force at Tindall.

Charlie Benjamin says Australia has left people of Manus Island with nothing but ‘bad memories’

Benjamin opposes the establishment of a US-Australia military base, another decision he said was made without the consultation or involvement of Manus people.

“That’s a problem I have to deal with, and it disappoints me the Australia and Papua New Guinea did not see this as a big problem,” he said. “We are not given enough help to deal with all of this.

“So when they come and say, ‘We want to build a military base in Manus’, I say ‘I already have experience with you Australians, dealing with asylum seekers, and my people were left out’. I don’t want our people to be left out again with this military exercise.”

He said the base was clearly of benefit to Australia and the US and in response to the growing influence of China in the region. “That has to come at a price,” he said. “You can’t just come in and expect me to welcome you, and face all the social problems, while your people are safe in Australia and America. “If there is a war we are the first ones to face the missiles and you will be safe in your country.”

The US military is considering investing more than $211 million into construction in Darwin, Australia, according to the Senate's version of the annual defense legislation.

What that money will build is unknown. The Marine and Navy officials Marine Corps Times reached out to have yet to provide a statement.

Australian outlet ABC News reported that secret planning is underway to develop a new commercial port just outside of Darwin that could eventually be developed to house Australia's landing helicopter dock ships or the US amphibious assault ships that ferry Marines around the globe.

While Australia is one of America's most important military allies in the Pacific, the military construction could cause diplomatic headaches for Australia and sour its relationship with China, which over the years has become more economically intertwined.

"...even our best allies, the Australians, they're with us from a military perspective, but economically they're tied to China," Maj. Gen. Daniel Yoo, the commander of the Marine Raiders, told Marine Corps Times in an interview during a May special operations conference in Tampa, Florida.

"And so they have a problem internal to their own country as far as there's some that feel they should be closer to China, because their economic health is dependent upon it."

Congress may review the Corps' plan to redistribute its forces across the Pacific.

The ABC is reporting senior defence and federal government officials conceded the proposal may anger China even though it would be built as an industrial port.

However if approved it could eventually accommodate “large amphibious warships” such as landing helicopter docks and US military ships.

The ABC said it approached the Defence Department and the US Embassy in Canberra for comment, but both are yet to respond to detailed questions on timing and costs.

In a statement, the department said “Defence has no plans for the development of a new naval facility in the Northern Territory” while the US embassy declined to comment.

The NT Government says it is unaware of any plans for a US war base in Darwin.

In his first official visit to Darwin in May, US Ambassador to Australia Arthur Culvahouse said US relations to Australia were expected to build in the coming years.

Gunn Point Rd recently underwent $38 million upgrades which saw the resealing of the 35km stretch of road as well as resealing of Murrumujuk Rd.

Days prior to the revelation that a new port which could be used by the US Marines was being planned on the edge of Darwin, a placard popped up on one of the city's main commuter arteries.

"No USA war base" blared the letters of the sign hanging off the Bagot Road pedestrian bridge, which neighbours land owned by Australia's Defence Department.

Other similarly slapdash carboard banners were also erected along the street.

Their appearance signalled that some within the tropical capital may have been aware of the impending news — and perhaps the rest of the region's residents shouldn't have been too surprised.

While nothing has yet been declared through official government or Defence channels, the signs of such a development have long existed.

Whether or not the NT will see more foreign boots on the ground, the ADF has been steadily improving and upgrading defence infrastructure in and around Darwin in recent years — a fact which falls somewhat contradictory to the reality that ADF numbers have been on a steady decline in Darwin for the past decade.