The treaty will be inked when Foreign Minister Penny Wong and Defence Minister Richard Marles host their UK counterparts David Lammy and John Healey in Sydney on Friday for regular Australia-UK ministerial meetings, according to British news agency PA.
"This historic treaty confirms our AUKUS commitment for the next half century," UK Defence Secretary John Healey said.
While the AUKUS nuclear submarine partnership involves the US, UK and Australia, the treaty is between the latter two nations, as a Pentagon review into the agreement threatens America's future participation.
Australia and the UK are expected to lay out the bilateral aspects of the agreement and explore ways the two countries can work together over the next half-century.
In a joint statement, Mr Marles and Senator Wong said the Australia-UK Ministerial Consultations, or AUKMIN, were critical to the two nations' shared interests.
"We take the world as it is - but together, we are working to shape it for the better," Senator Wong said.
Under the $368 billion AUKUS program, Australia will buy at least three Virginia-class nuclear-powered submarines from the US in the early 2030s. A new class of nuclear submarines will be built in Adelaide and delivered in the 2040s.
The US had promised to sell Australia nuclear-powered attack submarines under the AUKUS agreement, but President Donald Trump's administration has launched a review into the deal to examine whether it aligns with his "America first" agenda.
Defence analysts believe a likely outcome of the US review will be a request for more money from Australia to support its submarine industrial base.
The Australian government has said it remains confident in the nuclear-submarine deal being delivered.
The UK has fast become one of Australia's most important defence allies amid turmoil under the Trump administration, a security analyst says.
Australian Strategic Policy Institute senior analyst Alex Bristow said holding ministerial meetings on a six-monthly cycle, rather than the traditional annual timeline, highlights strengthened ties between the two nations.
"The tempo of it increasing, I think, is a signal that Britain is moving into an elite category," he told AAP.
The UK was probably third behind Japan and the US in terms of how strategically significant the defence relationship was to Australia, Dr Bristow said.
Meanwhile, the UK's Carrier Strike Group, led by the Royal Navy flagship HMS Prince of Wales, arrived in Darwin on Wednesday in the midst of the Talisman Sabre multi-nation military exercises being hosted by Australia.
It's the first UK carrier strike group to visit Australia since 1997.
The international task group includes five core ships, 24 jets and 17 helicopters, centred on the flagship aircraft carrier.
On Sunday, Mr Marles and Senator Wong will join their counterparts in Darwin to observe the UK Carrier Strike Group in action at Talisman Sabre.
UK High Commissioner to Australia Sarah MacIntosh said the arrival of the strike group was a demonstration of commitment to the region and the strong relationship with Canberra.
"This is an anchor relationship in a contested world," she said.
Dr Bristow said Australia should be welcoming carrier strike groups from European countries.
He said NATO had identified China as a threat to its interests as Beijing continues to collaborate with Russia and North Korea.
"It's entirely in the interests of European allies in NATO to be working with Indo-Pacific allies," Dr Bristow said.
with PA
