Australia will indefinitely detain people convicted of terrorism-related charges if it feels they pose an ongoing danger to society upon their release, Prime Minister Malcolm Turnbull said on Monday.
Turnbull compared the measures to those employed against some child-sexual offenders and cited what he called a growing number of attacks such as the recent Bastille Day attack in Nice, France, that killed dozens.
"The measures we are announcing today are designed to deter terrorism, prevent it, ensure that the nation and our people are kept safe," Turnbull told reporters on Monday.
"It will provide a very real incentive for people in prison for terrorist offences not to engage in continued extremist activity."
A staunch US ally, Australia has been on heightened alert for attacks by home-grown radicals since 2014, having suffered several "lone wolf" assaults, including a cafe siege in Sydney in which two hostages and the gunman were killed.
About 100 people have left Australia for Syria to fight alongside organisations such as Islamic State, Australia's Immigration Minister said last month.
Attorney General George Brandis, speaking with Turnbull in Sydney, said indefinite detention would be decided by a court-supervised process, which included medical and psychological assessments, and details of a prisoner's behaviour in custody.
There will be a periodic review, an annual report to parliament and a statutory review of the efficacy and need for the scheme after the first several years, Brandis said.
"I make no apology for the government taking the view that if a person, having served a sentence of imprisonment for a serious crime, shows every indication of a willingness to repeat that crime, to reoffend as soon as they are released, they should remain behind bars," Brandis told the ABC.