The Northern Territory government quietly approached the Defence Department, seeking to discuss Australia's nuclear submarine program, according to internal briefing documents.
Amid rising tensions in the Indo-Pacific region, Australia last year announced plans to build a fleet of nuclear submarines as part of the AUKUS defence pact with the United States and United Kingdom.
The Northern Territory's interest in the nuclear submarines has been revealed in a defence department briefing given to the incoming Albanese government after the May election.
The briefing was released under Freedom of Information laws in September, but the Northern Territory's approach to the department's Nuclear-Powered Submarines Taskforce has not been previously reported.
Large parts of the undated brief were redacted but a short section on "stakeholder engagement" was published in full.
"Domestic stakeholder engagement will be critical to the development and delivery of a nuclear-powered submarine," the briefing paper states.
"The Nuclear-Powered Submarine Taskforce has engaged the South Australian government and engagement with the Queensland and New South Wales governments is a priority.
"The Northern Territory government has initiated engagement."
The ABC asked what the Northern Territory government had sought to discuss with the taskforce, including whether it included the prospect of hosting the nuclear submarines in Darwin harbour.
A spokesperson for Chief Minister Natasha Fyles said: "The NT government is undertaking a review to assess the territory's suitability and readiness to support the Federal Government."
"Information regarding defence matters, including the nuclear submarine program, should appropriately be provided by the Department of Defence."
The Northern Territory government would not say when it approached the defence department about the nuclear submarine program.
Defence hints at 'services and support' that might be needed in Darwin harbour
Visiting Australian and international submarines are seen periodically in Darwin harbour.
But it is generally considered an unfavourable training ground or deployment point because of the long stretches of shallow waters stretching out from the coast.
A shortlist of three potential locations for a new base for the nuclear submarines — all of them on the east coast — was announced in the lead up to the federal election.
The defence department did not directly answer questions about discussions with the Northern Territory government.
But in a statement, a spokesperson said "the development of maritime services and support in Darwin harbour" was covered in "regular, productive discussions with the Northern Territory government on a range of initiatives".
"Australia's future nuclear-powered submarine capability will offer significant opportunities for industry involvement, both domestically and internationally," the spokesperson said.
US and UK nuclear subs should rotate through Darwin, advisor says
Last week, Four Corners revealed plans for the deployment of up to six nuclear-capable American B-52 bombers in the Top End, as part of an ongoing expansion of military activity in Australia's north.
Following the report, Deputy Chief Minister Nicole Manison was asked whether the deployment would put the Northern Territory at greater risk from potential adversaries.
She said the territory had "a very long and proud defence history" and listed the upgrades and new construction of new facilities currently underway in the Top End.
"I think territorians are very comfortable with that, they understand our strategic location and generally are very supportive of that defence investment," she said.
Defence and national security are among the key "growth" sectors the territory government hopes will drive its ambitious push to achieve a $40 billion economy by 2030.
To help maximise defence investment in the Top End, Labor created the Canberra-based position of Defence and National Security Advocate to lobby government and industry on the Northern Territory's behalf.
The current advocate, defence analyst Alan Dupont, declined an interview request.
But he has previously argued for a Nothern Territory role in the transition to nuclear boats, which may not be ready before Australia's current conventional fleet needs replacing.
"The navy's nuclear-powered submarines are unlikely to be in the water much before 2040," he wrote after the AUKUS deal was announced.
"Having our submariners train and operate as joint crews on American and British nuclear submarines rotating through Darwin and Perth would help fill the looming submarine capability gap."
