Defence Secretary John Healey said AUKUS is a "fundamental" part of the UK's future security and can help drive the newly elected British Labour government's growth agenda.
Just over a week into the job and fresh from a NATO summit in Washington DC, Mr Healey toured specialist steel manufacturer Sheffield Forgemasters alongside Mr Marles on Saturday.
There he reaffirmed the UK's commitment to AUKUS and emphasised its role in UK job creation.
"This is just one example of how our hugely important partnership with our Australian and American partners can help drive jobs and growth across Britain," Mr Healey said.
The submarine programme is expected to generate 7000 additional British jobs.
At its peak, there will be over 21,000 people working on programmes related to it in the UK supply chain according to the British defence ministry.
As part of a trilateral partnership with the US and the UK, Australia will acquire three Virginia class vessels and build its own SSN-AUKUS machines so that eight nuclear-powered submarines will be in Australian service by the 2050s.
The plan will cost up to $368 billion.
A partnership between the UK, US and Australia, AUKUS's primary goal is to help Canberra attain nuclear-powered submarines amid rising tensions in the Indo-Pacific.
The trilateral pact also involves co-operation on a variety of other military technologies.
Mr Marles also visited His Majesty's Naval Base Clyde in Scotland to see first-hand how the UK operates its nuclear submarine base.
His Majesty's Naval Base Clyde is home to world class training and expertise in the operation of nuclear-powered submarines. — Richard Marles (@RichardMarlesMP) They have leading facilities to train submariners as well as sustain and maintain submarines.@RoyalNavy pic.twitter.com/1xrLhGVo0aJuly 12, 2024
The first three Royal Australian Navy officers will soon begin practical training on UK Astute class submarines at that navy base, after graduating from the Royal Navy's Nuclear Reactor Course this week.
Mr Marles said it was "a significant milestone in developing the skilled workforce required to operate Australia's future nuclear-powered submarines".
"Australia, the United Kingdom, and the United States are strongly committed to continued implementation of AUKUS. It is great to see real progress being made towards our national submarine programs," Mr Marles said in a statement.
The visit comes after UK Prime Minister Sir Keir Starmer spoke to his Australian counterpart Anthony Albanese with the leaders outlining their commitment to partnership.
Although concerns over the plan's costs, workforce capability, and nuclear waste management linger, a 2024 Lowy Poll found almost two-thirds of Australians are in favour of acquiring nuclear-powered submarines.