More terror supporters in Aust: Dutton

Terrorist sympathisers and extremist supporters in Australia are increasing in numbers and becoming more determined, Immigration Minister Peter Dutton says.

Delivering a ministerial statement on Operation Sovereign Borders, Mr Dutton says the number of Australians attempting to join extremist groups has increased in recent years and more will inevitably try to join.

"Sympathisers and supporters of extremists here are growing in number and determination," he told parliament on Wednesday.