ASIO boss Mike Burgess told an inquiry in Canberra on Thursday that Sunni-based violent extremism remained the biggest concern of security agencies, based on the current caseload, but nationalist, racist, misogynist violence is the fastest-growing threat.

"There is likely to be a terrorist attack in the next 12 months," Mr Burgess told the Parliamentary Joint Committee on Intelligence and Security's first hearing on extremism.

"It can come from either ideology and therefore for me doesn't really matter, because they're both capable of conducting acts of violence and that's where we focus."

The sharing of intelligence on the global trend reaches well beyond Australia's traditional Five Eyes partners - the US, UK, Canada and New Zealand - to include European countries facing white supremacist ultra-nationalism after decades of Islamic extremism.

"There is an increasing focus on the extreme right wing," Ambassador for Counter-Terrorism Roger Noble told the inquiry.

"I don't see a drop in the focus on religiously motivated violent extremism, particularly ISIL and Al-Qaeda, but there is a definite coincident rise on the extreme right-wing side."

"Operational issues" prevented the federal police from sharing details about stopping a paramilitary training network called The Base that has been recruiting in Australia.

The group was designated as a terrorist entity by Canada in February 2021, but Australia hasn't followed suit.

Australian Federal Police Deputy Commissioner Ian McCartney agreed religiously motivated violent extremism was still the principal threat but racist nationalism was the fastest-growing.

"The internet is a salad bar of hate," he said, and warned of gaps in law to restrict online radicalisation.

"Police are limited in the actions we take."

Possession and sharing of propaganda and extremist flags and insignia needed to be criminalised to deter mobilising people towards violence, the AFP warned.

Assistant commissioner for counter-terrorism Scott Lee said nationalist ideologies, inspired by individuals or groups overseas, were combining with racist ideologies, whether anti-Indigenous, anti-Asian or anti-Semitic.

Lonely, vulnerable, disaffected youth who then work alone or in small groups were sharing extremist material, insignia, dialogue and violent videos, the inquiry was told.

Australians as young as 13 and 14 are involved in Islamic extremist and extreme right-wing circles.

"They're engaging online in bedrooms," Assistant Commissioner Lee said.

"When we speak to their parents, they've got no visibility at all on what they're doing and certainly, depending on their background, and they're nowhere near as digitally literate as their children."

In March, the government made its first far-right listing when it banned the UK-based neo-Nazi Sonnenkrieg Division as a terrorist organisation.

Previously, Islamic and separatist groups made up the list of more than two dozen organisations banned under Australia's criminal code.

Home Affairs Deputy Secretary Chris Teal said listing an organisation was an important symbolic action, while Mr Burgess rejected calls from Labor to list more white supremacist organisations.

"Listing an entity will not stop a violent attack," Mr Burgess said.

Nor would it stop ASIO from disruption and surveillance operations, he said.

Sunni-based extremists remain mostly city-based, while right-wing threats are spread through the community.

ASIO was facing a "growing assortment of ideologically violent extremists", Mr Burgess said.

"We need to know why people are driven to these views."

The new cohort of extremists are more dispersed, tend to be more inspired by previous acts and manifestos, and their targets are different.

Racist nationalist groups have risen from one-third of ASIO's caseload to 40 per cent in the past year, up from just 16 per cent three years ago.

Australian Associated Press