Australia will commit about $28 billion through 2040 to increase its active military personnel by a third to keep the country safe "in an increasingly uncertain global environment, said Prime Minister Scott Morrison, Reuters reported.

Australia has been increasing its defense spending in recent years.

Last year, Australia struck a deal to buy nuclear submarines with the US and the UK.

The planned expansion will bring the number of troops to 80,000, a level not seen since the Vietnam War.

Defense Secretary Peter Dutton said it was critical to complement Australia's defense capabilities to make it a reliable partner"for the US, UK and NATO.

Last week, the leaders of the Quad - the US, India, Australia and Japan - agreed that what is happening with Ukraine should not be allowed in the Indo-Pacific amid fears over Taiwan.