Malcolm Turnbull is being urged to move cautiously on new anti-terrorism laws, which he says are needed to respond to the growing number and severity of attacks across the world.
"The threat is real," the prime minister said, unveiling two new tranches of anti-terrorism legislation in Sydney on Monday.
"We can never ever be complacent and we are not - we are focused constantly on the single most important obligation of our government ... which is to preserve and protect the safety of the people."
Over the past year, 750 people have been killed in 40 attacks in the west or against western interests.
Mr Turnbull will work with state and territory leaders to roll out a system of post-sentence preventative detention for terrorists at high risk of reoffending.
The process will be overseen by the courts and informed by detailed medical and psychological checks.
The Law Council and shadow attorney-general Mark Dreyfus said the new powers should only be used in the most extreme cases.
"That would be where an unacceptably high ongoing risk is posed to the community and there has been no rehabilitation of the prisoner during his or her original sentence," Mr Dreyfus told reporters in Sydney.
"Checks and balances on this new power are going to be crucial to prevent the possibility of legislative over-reach or unjust deprivation of liberty."
Mr Dreyfus said the government should seek advice from the solicitor-general on the constitutionality of the bill, which will likely need Labor's support to pass parliament.
The prime minister also revealed the government would adopt the recommendations of a parliamentary committee which looked at the previous tranche of anti-terrorism legislation and this would be put to parliament as soon as possible.
The bill, which was introduced late last year, extends control orders to juveniles to the age of 14, down from 16. It will also introduce a new offence of advocacy of genocide.
Attorney-General George Brandis said juveniles were in a different position to adults even though they were potentially just as dangerous.
Senator Brandis will meet with state and territory attorneys-general in coming days to discuss the new laws.
The preventative detention change would match similar laws already in place for sex offenders and violent criminals in some states and comes after leaders agreed to the scheme at the meeting of the Council of Australian Government in Canberra in April.
Senator Brandis says the laws would be reviewed on a periodic basis.
He refused to comment on whether there were terrorists in jail now who would be kept behind bars as a result of the proposed laws, and said he was "reasonably confident" of the laws surviving a High Court challenge.
Mr Dreyfus said it was also important the government did not send "contradictory messages" about its approach to extremism, given calls by some coalition figures such as Dawson MP George Christensen for a ban on Muslim migrants.