Foreign Secretary David Lammy and Defence Secretary John Healey will meet their Australian counterparts Penny Wong and Richard Marles at the annual Australia-UK ministerial meeting, or Aukmin, in Sydney.
They will then travel on to Melbourne to meet businesses involved in the AUKUS submarine program.
They will also visit Darwin as the UK Carrier Strike Group docks in the Northern Territory.
The AUKUS partnership between the UK, US and Australia involves building nuclear-powered attack submarines - including Australia acquiring its first such fleet - and co-operating in other areas of defence.
It was agreed by the three countries in 2021, but the Trump administration has put it under review, raising fears it could pull out.
The deal now being signed by the UK and Australia sets out the bilateral aspects of the partnership and how the two countries will work together to deliver the AUKUS submarine program over the next half-century.
"AUKUS is one of Britain's most important defence partnerships, strengthening global security while driving growth at home," Healey said.
"This historic treaty confirms our AUKUS commitment for the next half century."
He said people "not yet born" will benefit from jobs secured through the deal.
More than 21,000 people in the UK are expected to be working on the program at its peak.
Lammy said the UK-Australia relationship is "like no other".
"In our increasingly volatile and dangerous world, our anchoring friendship has real impact in the protection of global peace and prosperity," he said.
"Our new bilateral AUKUS treaty is an embodiment of that - safeguarding a free and open Indo-Pacific whilst catalysing growth for both our countries."
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