AUKUS trilateral statement

Release details

Release type

Related ministers and contacts


The Hon Richard Marles MP

Deputy Prime Minister

Minister for Defence

Media contact

dpm.media@defence.gov.au

02 6277 7800


The Rt Hon Grant Shapps

Secretary of State for Defence, United Kingdom


Lloyd J. Austin III

Secretary of Defense, United States

Release content

22 March 2024

One year ago, on 13 March 2023 in San Diego, the Leaders of Australia, the United Kingdom, and the United States announced the Optimal Pathway. The Optimal Pathway outlines an ambitious plan to deliver a conventionally armed, nuclear-powered submarine capability (SSNs) for the Royal Australian Navy – a plan that will strengthen our three countries’ combined military capabilities, boost our collective industrial capacity, set the highest non-proliferation standard and enhance our ability to promote stability and security in the Indo-Pacific and beyond. 

AUKUS is built on the bedrock of decades of close defence, capability and technology cooperation between our three nations and is a natural progression of our partnership. Today, AUKUS partners welcomed the announcement of the selection of ASC Pty Ltd and BAE Systems to build Australia’s SSN-AUKUS submarines, and the selection of ASC as Australia’s nuclear-powered submarine sustainment partner. 

The formation of these strategic partnerships with industry is a significant milestone in the AUKUS endeavour. It is a demonstration of our trilateral industry supporting the Optimal Pathway becoming a reality and will underpin Australia’s role as a capable security partner and responsible steward of a conventionally armed, nuclear-powered submarine capability for decades to come. 

The enduring trilateral partnership between the governments of Australia, the United Kingdom and the United States supports these commercial relationships and further enables the close industrial collaboration across our three countries in support of AUKUS. 

ASC and BAE Systems will build the SSN-AUKUS submarines for the Royal Australian Navy. BAE Systems has been at the heart of the UK’s submarine enterprise for generations. SSN-AUKUS is being trilaterally developed, based on the United Kingdom’s next-generation design and incorporating technology from all three nations, including cutting edge United States submarine technologies. Also to be built by the UK and operated by the Royal Navy, SSN-AUKUS will be equipped for intelligence, surveillance, undersea warfare and strike missions, and will provide maximum interoperability among AUKUS partners. 

ASC has been at the centre of Australia’s sovereign submarine program for decades as Australia’s sovereign submarine sustainment partner, and the builder of Australia’s Collins-class submarines. ASC will build its sustainment capability for SSNs, including through partnering opportunities with UK and US industry. Sustainment capability is critical to the Optimal Pathway, accelerating Australia’s ability to operate and sustain its own Virginia class submarines as soon as possible and contribute to regional security, together with AUKUS partners. 

The Optimal Pathway was always designed to create a stronger, more resilient trilateral submarine industrial base, supporting submarine production and maintenance in all three countries. The announcements today are a testament to that - the build of SSN-AUKUS will increase opportunities for industrial base collaboration, strengthen our collective industrial base capacity, and generate economic growth in defence and national security sectors in all three countries. Similarly, the announcement of Australia’s sovereign sustainment partner is a key milestone to build Australia’s capacity to operate and sustain nuclear-powered submarines. ASC will, in time, develop robust industry partnerships with UK and US businesses to gain the technical skills, know-how and capacity to sustain nuclear-powered submarines. 

All AUKUS partners are investing significantly to ensure success of the Optimal Pathway and are working at pace to transform and integrate our trilateral industrial bases to support SSN cooperation. 

• Australia has agreed an AUD $1.5 billion investment for early priority works at HMAS Stirling, to put in place the enablers for the safe and secure rotational presence of United Kingdom and United States SSNs through Submarine Rotational Force-West from 2027. Australia has also commenced enabling works at the future nuclear-powered submarine construction yard at Osborne Naval Shipyard in Adelaide. All up, Australia has committed at least AUD $18 billion in infrastructure upgrades across South Australia and Western Australia over the next 10 years to enable critical milestones for the Optimal Pathway. 

• The United States has announced the intended investment of USD $11.4 billion in its submarine industrial base across the five-year defense budget period starting in 2025 to increase the production rate of Virginia class submarines as quickly and effectively as possible, to meet its own fleet requirements and support US commitments under AUKUS. 

• The United Kingdom also announced last year that it would inject GBP £3 billion into its Defence Nuclear Enterprise, including the construction of submarine industrial infrastructure that will help to deliver the SSN-AUKUS program. Subsequently, Rolls-Royce has announced that it will double the size of its Derby site to support the delivery of the UK and Australian programs, which will include building all of Australia’s nuclear reactors. 

Australia, the United Kingdom, and the United States remain fully committed to this shared endeavour. These steps to grow Australia’s submarine construction and maintenance capability are critical to the AUKUS partnership, expanding trilateral industrial capacity and building the collective resilience of AUKUS partners to produce and sustain conventionally armed nuclear-powered submarines for decades to come.

Other related releases