Foreigners will be able to join the Australian Defence Force, under a fast track to citizenship, as a personnel shortage is forecast to reach almost 5000 over the next 12 months.
As part of the national defence strategy unveiled in April, eligibility criteria will be expanded to allow more people to join the defence force.
From July, eligible New Zealanders can apply to join the Australian military.
Permanent residents from the UK, US, Canada and the Pacific Islands can do the same from January 2025.
Once they have served for 90 days, they will be expected to become Australian citizens.
Defence Personnel Minister Matt Keogh was forced to clarify which nationalities were eligible, after he initially said foreigners from all countries could join.
"It's all been made very clear actually ... from 1 January we expand that out to other Five Eyes countries ... then we'll also look to expand to other countries looking with a particular focus on Pacific Islands," he told ABC News.
The government's announcement on Tuesday only listed citizens from New Zealand, the UK, US and Canada.
Pressed on whether permanent residents from other countries were eligible, Mr Keogh replied that was "something that would evolve over time".
The government expects the changes to bring in an additional 350 people each year.
The federal budget handed down in May shows the estimated defence workforce will be 58,600 by June 30 next year, against a requirement of 63,597 personnel.
Non-citizens who want to join the military must have lived in Australia for at least one year before applying, must not have served in a foreign military in the previous two years and must be able to attain Australian citizenship.
They will also undergo security checks.
Asked about the changes, Defence Minister Richard Marles said the government had improved the conditions offered to defence personnel through a more generous housing package and retention bonuses.
"It is an important step to open the door to a broader range of people to join our defence force," he told parliament.
Opposition Leader Peter Dutton criticised Labor's handling of the proposal, labelling it a "dog's breakfast".
Opposition defence spokesman Andrew Hastie said the government had given up on fixing the recruitment and retention issues.
"Servicing the ADF is one of the most exciting, rewarding, challenging things a young Australian can do, and they have not made that argument at all," he said.
Australian National University expert associate Jennifer Parker said the change was a positive step, if not a major initiative.
"It will likely only have an incremental change in the recruiting numbers," she told AAP.
"But this is the direction we need to be going in - thinking laterally about who and how we recruit."
The federal budget in May secured an extra $5.7 billion for the defence force over the next four years and an additional $50 billion over a decade.
