The UK has launched a parliamentary inquiry into the AUKUS military arrangement between it, Australia and the US.

AUKUS Pillar One aims to deliver nuclear powered submarines to Australia while Pillar Two has seen the trio beginning to engage in advanced military tech development and sharing under reduced US military trade barriers.

The House of Commons Defence Committees said the inquiry was into whether AUKUS is on track and progress under each pillar.

It would also "consider the impact of geopolitical shifts since the initial agreement in 2021".

None of the leaders who signed it - Boris Johnson, Joe Biden and Scott Morrison - are still in office, and this year the US has shifted away from its European NATO allies.

Former Australian Prime Minister Malcolm Turnbull has been leading the anti-AUKUS charge across the Tasman, questioning whether the country will ever actually own a US nuclear-powered submarine.

A top Pentagon official has questioned the wisdom of the sub deal when US shipbuilding is underpowered and its sub fleet faces being under-strength.

New Zealand is still considering whether to join Pillar Two.

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A ministerial briefing said the potential risks of not participating in it included to New Zealand's "relationships with close partners, interoperability, access to important capabilities, ability to contribute credibly to regional defence and security, and economic impact (including supply chain access)".

The new UK inquiry would be asking, "What are the opportunities and challenges involved in the potential expansion of Pillar 2 beyond the three partner nations?"

US thinktanks have been looking to AUKUS to break a longstanding US reluctance to share weapons technology for development outside its borders.

"The lack of a unified Indo-Pacific defence innovation framework has become increasingly apparent," said the Atlantic Council in an opinion piece last month.

The US Defence Department's Innovation Board has stated, "AUKUS is the primary opportunity for the DoD to get openness and collaboration right" but also warned, "AUKUS is far from a guaranteed success."

Its other observation was that "outside of AUKUS, the DoD is not adequately integrating key allies and partners, thereby leaving significant resources and capabilities underutilised", and it must do more to integrate "emerging partners".

Pillar Two technologies include: undersea capabilities, quantum technologies, artificial intelligence and autonomy, advanced cyber, hypersonic and counter-hypersonic capabilities and electronic warfare.