'Least curious and least informed': what is AUKUS and why does it matter?

AUKUS is a three-nation security pact between Australia, the US and the UK, brokered in 2021 when Scott Morrison was prime minister.

Mr Morrison controversially dumped a deal with France to supply diesel-powered submarines in favour of the partnership which is designed to deliver nuclear-powered submarines instead.

Pulling out of that deal ultimately cost Australian taxpayers about $3.4 billion and strained diplomatic relations with France.

AUKUS is widely seen as response to China's strategic moves and growing influence in the Pacific.

Under the partnership, Australia is set to acquire three Virginia-class submarines from the US in the early 2030s before a new fleet of boats is built for delivery from the 2040s.

But the US is lagging in production of the boats, and the American president can sink the deal if his navy's capabilities are at risk, which is why the review flagged by the Pentagon has some people worried.

It's estimated AUKUS will cost Australia about $368 billion and ultimately deliver at least eight nuclear-powered submarines, some of which would come from the US.

In February, Australia made the first of six $800 million payments to the US under the deal.

The UK recently completed a review of its involvement in AUKUS review and reiterated its support.

Critics of AUKUS point to the lagging production of boats in the US and have warned the deal might jeopardise the US navy's capabilities.

The US is also pressuring Australia to raise its defence spending to 3.5 per cent of gross domestic product, while President Donald Trump wants to double tariffs on imported steel from 25 per cent to 50 per cent.

Former prime minister Malcolm Turnbull took to social media on June 12 to declare America's AUKUS review was a "wake up call".

"But Australia, which has the most at stake, has no review. Our parliament to date has been the least curious and least informed," he wrote on X.

"Time to wake up?"

Former South Australian independent senator and transparency warrior Rex Patrick said it was time to "pull the plug" on AUKUS.

"The program is an unaffordable, sovereign sapping and highly risky defence acquisition - a huge blunder of [Scott Morrison], embraced by [Prime Minister Anthony Albanese]," he wrote, also on X.

"Trump will likely demand more $ billions, or else exit. We should pull the plug."

Australia's defence minister, Richard Marles, played down the US review, saying it was "natural" the Trump administration would want to re-examine the partnership, which was forged under the leadership of former president Joe Biden.

- with Australian Associated Press