Australia, a staunch ally of the United States and its battle against Islamist militants in Iraq and Syria, said on Friday it would strip dual nationals convicted of terrorism-related crimes of citizenship.

French President Francois Hollande last month abandoned plans to strip French nationality from people convicted of terrorism, climbing down from a tough stance that he took days after the November attacks in Paris, which killed 130 people.

Dual nationals who are either involved in terrorist activities, members of a banned organization or convicted of terrorism offenses could lose their Australian citizenship, Immigration Minister Peter Dutton told reporters in Melbourne.

"There is a very significant penalty to pay if people are involved in terrorist activities and they're a dual national," said Dutton.

Australia has been on heightened alert for attacks by home-grown radicals. While nearly 200 people were suspected of being a domestic threat, Dutton said approximately 100 people had left Australia for Syria to fight alongside organizations such as the Islamic State.

In addition, the Australian Security Intelligence Organisation was working on 400 "high-priority investigations" related to potential security threats, Dutton said.