A multi-billion dollar submarine deal between long-standing allies – Australia, the UK and the US – has come under the spotlight after the Trump administration said it was reviewing how the deal fits in with its heavily-touted “America First” agenda.

The Aukus security pact, Australia’s biggest ever defence project, is set to play a key part in the country’s ability to replace its ageing Collins-class submarine fleet – and, crucially, its military standing in the region.

The 30-day review will be led by Elbridge Colby, who has previously been critical of Aukus. In a speech last year, he questioned why the US would give away “this crown jewel asset when we most need it”.

A US defence spokesperson said the review is about ensuring “this initiative of the previous administration is aligned with the President’s America First agenda”.

Fears the review may torpedo the deal have been downplayed by the UK and Australia, with both saying the review is a normal process when a new government takes power.