Under the plan, Australia will get a navy of 26 major surface combatant ships, up from 11 today.

"It is the largest fleet that we will have since the end of the Second World War," said Defence Minister Richard Marles.

Australia will build six Hunter class frigates, 11 general-purpose frigates and six state-of-the-art surface warships that do not need to be crewed.

At least some of the fleet will be armed with Tomahawk missiles capable of carrying out long-range stand-off strikes on targets deep inside enemy territory -- a major deterrent capability.

The announcement comes after a massive build-up of firepower by rivals China and Russia, and amid growing confrontation between nervous US-led allies and increasingly bellicose authoritarian governments.

The plan would see Australia increase its defence spending to 2.4 percent of gross domestic product, above the two percent target set by its NATO allies.

Some of the ships will be built in Adelaide, ensuring more than 3,000 jobs, but some will be sourced from US designs and a still undecided design from Spain, Germany, South Korea and Japan.