Some 110 Australians are now thought to be fighting in Iraq and Syria, mostly for Islamic State, with more than 40 believed killed, Attorney-General George Brandis says.
Senator Brandis said the latest intelligence estimate indicated about 190 people in Australia were providing support to individuals and groups through funding and facilitation with some seeking to travel themselves.
Around 146 passports of those seeking to travel to the Middle East to join the conflict had now been cancelled, up from 60 in September 2014.
Addressing the Centre for Independent Studies in Sydney, he said 110 Australian fighters might not seem that many, especially when set against the scale of the conflict.
But it was more than either the US or Canada.
Senator Brandis said at least 41 Australians are believed to have been killed, around 26 in the past year.
He said domestic terrorism was of more immediate concern, with 25 arrested in 10 counter-terrorism operations since the terror alert level was raised from medium to high 14 months ago.
"To put that into perspective, that is more than one third of all the arrests for terrorism related offences which have taken place in Australia since September 11, 2001," he said.
"As of today, there are some 400 high priority ASIO counter-terrorism investigations being carried out."
Senator Brandis said he would introduce the fifth tranche of counter-terrorism legislation to parliament next week, including the new crime of advocacy of genocide.
He said advocacy of genocide could never be regarded as an expression of radical political opinion.
"Yet advocacy of genocide does go on, unpunished, in Australia today in particular, directed against Jewish people and against the state of Israel," he said.
The bill will also implement controversial measures which allow control orders to be imposed on people as young as 14.
