SYDNEY (AFP) - Australian Prime Minister Scott Morrison announced on Tuesday (March 15) his government is readying the country's ports to host nuclear-powered submarines from Britain and the United States.

Mr Morrison said his defence department would determine what was needed "to support the more frequent presence" of nuclear-powered submarines from the two ally nations.

The move could provide the two nuclear powers with better access to the Indian Ocean and the South Pacific, challenging China's growing maritime power.

Mr Morrison said the decision was part of the Aukus partnership - referring to the defence agreement inked last year between the US, Britain and Australia.

Under Aukus, Australia will become the first non-nuclear country to have nuclear-powered submarines.

Mr Morrison said US and British nuclear-powered submarines would initially be hosted at Australia's remote west coast - on the Indian Ocean - but added that he "would ultimately like to see them on the east coast as well".

Ahead of a looming federal election, Mr Morrison has flagged a number of expansions of Australia's defence capability, including boosting the country's defence forces by a third to 80,000 personnel by 2040.