The United States has launched a review of the landmark Aukus submarine pact with the United Kingdom and Australia, signalling it wants the multi-billion-dollar agreement to align more closely with the new administration’s ‘America First’ policy.

The trilateral security agreement, signed in 2021, was seen as a strategic move to counter China’s growing influence in the Indo-Pacific. Under the deal, Australia is set to acquire nuclear-powered submarines — first from the US, then through a joint programme with the UK — using cutting-edge defence technology shared between the allies.

A senior US defence official confirmed to the BBC that the review is part of efforts to ensure initiatives inherited from the previous administration are in line with current priorities. “As [US Defence] Secretary [Pete] Hegseth has made clear, this means ensuring the highest readiness of our servicemembers [and] that allies step up fully to do their part for collective defence,” the official said.

The review will be led by Elbridge Colby, a prominent figure in US defence policy circles who has previously criticised Aukus for what he called giving away the “crown jewel” of American military technology. Colby’s appointment underscores the seriousness with which the administration is reconsidering its defence posture amid global tensions, especially over Taiwan.

Allies react cautiously

Officials in both the UK and Australia sought to play down the implications of the review, describing it as a routine step for any incoming administration.

Australian Defence Minister Richard Marles, speaking to ABC Radio Melbourne on Thursday, expressed confidence that the deal would move forward as planned. “I’m very confident this is going to happen,” Marles said. “You just need to look at the map to understand that Australia absolutely needs to have a long-range submarine capability.”

Canberra also acknowledged the review but characterised it as a natural part of the transition to the Trump administration. A government spokesperson said there is “clear and consistent” bipartisan support for Aukus in the United States, and that Australia looks forward to “continuing our close cooperation with the Trump Administration on this historic project.”

The UK, which conducted its own review of the Aukus pact last year, echoed similar sentiments. A spokesperson for the Ministry of Defence said it was “understandable” that a new administration would wish to examine such a significant deal. “Aukus is a landmark security and defence partnership with two of our closest allies,” the spokesperson said. “It is one of the most strategically important partnerships in decades, supporting peace and security in the Indo-Pacific and Euro-Atlantic.”

Push for higher defence spending

The review also comes amid increasing pressure from Washington for allies to boost their defence budgets. The US is urging partners to spend at least 3% of their GDP on defence — a target the UK has committed to reach in the next parliament, after increasing its target to 2.5% by 2028. Australia, meanwhile, has pledged additional funding but has stopped short of the 3.5% threshold reportedly sought by the US.

Observers suggest that Washington’s reassessment may be driven in part by concern over its own stretched submarine fleet and a desire to ensure that its allies are equally committed to the collective security agenda.

Jennifer Kavanagh, a defence analyst from the Washington-based think tank Defense Priorities, said the US was “absolutely right” to reassess the deal. “The US cannot meet its own demand for these nuclear-powered submarines,” she noted. “It’s also a valid question whether Australia would use these submarines the way the US wants them to — particularly in the event of a conflict over Taiwan.”

Kavanagh added that the review could shift the focus of Aukus away from submarine transfers toward cooperation on other long-range weapons and technologies.

Background of the pact

Aukus was announced in September 2021 by then-leaders of the US, UK and Australia — Presidents Joe Biden, Prime Minister Boris Johnson, and Prime Minister Scott Morrison. The agreement was widely viewed as a diplomatic coup for Canberra, though it sparked tensions with France, which saw its own submarine deal with Australia abruptly cancelled.

Under the current arrangement, Australia will initially acquire three second-hand Virginia-class submarines from the US in the early 2030s, with the option to purchase two more. In the longer term, the plan is to co-develop a new nuclear-powered submarine platform — dubbed SSN-Aukus — built in the UK and Australia using joint technology.

Starting from 2027, a small number of US and UK submarines will be deployed to HMAS Stirling naval base in Perth, Western Australia, to deepen interoperability between the three navies.

China criticises deal

Beijing has consistently opposed the Aukus agreement, with the Chinese foreign ministry accusing the trio of fuelling an arms race in the Indo-Pacific. While Washington and its allies maintain that the pact is aimed at promoting regional security, China sees it as a containment strategy.

Still, experts warn that any indication of the US backtracking on Aukus could be interpreted as a diplomatic victory for Beijing.

“If the US pulls out or scales down its commitment, China would celebrate,” said Kavanagh. “It would be a major blow to allied deterrence efforts in the region.”