CANBERRA (BLOOMBERG) - Australia expects to soon announce more specifics of a plan to acquire nuclear-powered submarines under a security partnership with the US and Britain, Defence Minister Peter Dutton said.

Prime Minister Scott Morrison in September announced the new defence alliance and moved to scrap a deal struck in 2016 with French shipbuilder Naval Group to build as many as 12 diesel-powered vessels, a project that had blown out to an estimated A$90 billion (S$90.2 billion).

"We will have an announcement within the next couple of months about which boat we are going with, what we can do in the interim," Mr Dutton told Australian Broadcasting Corp television on Sunday (March 6).

"Both the US and the UK understand the timelines, they understand what is happening in the Indo-Pacific, and they are very, very willing partners."

The partners had initially said work on the details and specifications could potentially take 18 months. Mr Morrison's government faces a national election that must by held by May.

Australia's investment is intended to replace an ageing fleet of Collins Class submarines.

Mr Dutton indicated Australia hoped to have its first nuclear-powered vessels before 2040, the current date by which they're expected to be in service.

"We are going to acquire the capability much sooner than that," he said. "The arrangement that's underway at the moment between the US and UK has been incredibly productive."