Australia’s submarine boss has admitted there will be setbacks and difficulties with the navy’s acquisition of nuclear-powered submarines, amid growing scrutiny over whether the AUKUS pact can be delivered.

But while making the concession, Vice Admiral Jonathan Mead rebuffed criticism that AUKUS was at risk of failure, leaving Australia with no submarine capability. Key milestones were on track to be met so that US and UK submarines would begin being deployed from Perth from 2027, he said.