The United States' armed forces will spend more than a quarter of a billion dollars upgrading their air defence capabilities in Darwin, the Northern Territory's Chief Minister has revealed.

Key points: The ABC revealed in July this year that a draft US Congressional bill had $US211.5 million allocated for new "Navy Military Construction" in Darwin

The ABC revealed in July this year that a draft US Congressional bill had $US211.5 million allocated for new "Navy Military Construction" in Darwin NT Chief Minister has confirmed he reached out and established that the money would be spent on ramps for the Ospreys

NT Chief Minister has confirmed he reached out and established that the money would be spent on ramps for the Ospreys Territory businesses could stand to benefit from the increased defence spending

The US Defence Department is looking to spend $305.9 million on facilities for their Osprey fleet, Chief Minister Michael Gunner told NT Parliament on Wednesday, while knocking back a suggestion that the money would be spent on a new naval base in Darwin.

"The budget appropriation that is being sought in America is for ramps for the Ospreys in the Northern Territory, not for a naval installation," Mr Gunner said.

"The Ospreys are aircraft vehicles. That is where the money is intended to go."

Darwin has long been pegged as a Pacific strategic hub as geo-political tensions continue to grow between China and the US in the South China Sea.

The news comes just over a week since Prime Minister Scott Morrison hosed down suggestions that US missiles could be deployed in Darwin.

The US has an annual rotation of Marines through Darwin. ( Supplied: Australian Defence Force )

In July, the ABC revealed that a draft US Congressional bill had $US211.5 million allocated for new "Navy Military Construction" in Darwin, with few other details available.

Mr Gunner said that following these reports, he had reached out to US Secretary of Navy Richard Spencer, to clarify the nature of the spending.

"Whether it is for the Marines or the Air Force, the money to be spent in the Northern Territory by the US has come through the Naval appropriations," he said.

"Having seen those reports, I thought I would clarify that with the US Secretary of the Navy directly. He came back and said it was for the ramps for the Ospreys."

The ABC understands plans for a new commercial port facility were still being discussed.

There had been a rumour the money would go to a new port facility. ( ABC; Michael Donnelly )

New industry opportunities highlighted in light of increased spending

Mr Gunner said Northern Territory businesses, and the region's ailing economy, could hope to secure a boost through the upcoming US spend in the region.

The US already has an annual rotation of marines stationed in Darwin, which hit its peak this year at 2,500 soldiers.

"The US has been very open to those conversations," he said.

Australian Industry Defence Network NT CEO Kerryn Smith said she had been working with US authorities "to look at how we can better position our Australian suppliers and our local suppliers here in the NT to take up those opportunities".

Mr Gunner also said a proposed new ship lift facility, which the NT Government has pledged to build for $400 million of taxpayer funds, could be used by US or other foreign ships for repairs on an "as-needs basis".

"I do think this provides the capacity for vessels to be repaired in Australia in the only deep water port in the north," he said.

The ADF will also use the ship lift on an "as-needs basis", he said, after the Darwin-based Coonawarra Naval Base is decommissioned in 2024.

Calls for a federal review into Australian Defence Force presence in the NT

Darwin has long been seen as a Pacific strategic hub. ( Supplied: Australian Defence Force )

Mr Gunner also called for a federal review into the Australian Defence Force's (ADF) troop positioning to assess if there were "adequate [forces] in the north of the country".

"This is a reasonable question for the Australian Government to consider — strategically," he said.

If it went ahead, it would be the first review into the ADF posture since 2012.

Former Labor leader Bill Shorten promised a force posture review prior to the May election, saying "we now face the most challenging set of strategic circumstances since the Second World War".

Numbers of ADF members based in the NT have been on a steady decline now for a decade.

A spokesperson for the ADF said their presence in northern Australia remained vital to supporting their strategic defence interests.

"The Defence White Paper commits the Government to a strengthened Australian Defence Force (ADF) presence in northern Australia, including new infrastructure projects and ADF capabilities that will operate through northern Australia over the next decade and beyond," they said.