As the Trump administration signals a review of the AUKUS agreement (a military and security partnership between Australia, the UK, and the US), the UK and Australia have announced a 50-year treaty to deepen their cooperation under AUKUS. The move reaffirms their strong commitment to the pact.
UK Defence Secretary John Healey called the treaty “historic” and said it confirms the UK and Australia’s long-term strategic commitment to AUKUS over the next five decades. He stressed that AUKUS strengthens global security and supports domestic economic growth. Healey and Foreign Secretary David Lammy are currently visiting Australia for annual defence and foreign affairs talks.
UK officials told the ABC that the treaty is aimed at showing the US that UK-Australia support for AUKUS remains firm—regardless of political shifts in Washington. The signing comes as Darwin hosts the largest-ever “Exercise Talisman Sabre”, and the UK aircraft carrier HMS Prince of Wales is docked there.
Although full details are not public, the deal is expected to create around 7,000 UK jobs and generate over AUD 40 billion in export income within 25 years. The Australian government has pledged over AUD 4 billion to support UK submarine construction and nuclear reactor supply. Both countries will co-design and build a new generation of nuclear-powered submarines.
Still, the total cost of the AUKUS program has raised concerns. Australia earlier estimated a price tag of at least AUD 368 billion, with experts warning of potential cost increases due to inflation and delays. Greater Australian investment in the UK could also trigger political scrutiny and domestic opposition.
Despite these challenges, the treaty signals that both countries see sustaining and deepening AUKUS as a key part of their long-term Indo-Pacific strategy in response to China’s growing regional influence.