An international unit aimed at countering extremism and radicalisation will receive $2.5 million in funding from Australia, Prime Minister Malcolm Turnbull has announced.

The initiative was announced at a meeting between Commonwealth heads of government in Malta, and has also been financially backed by the United Kingdom.

Australia will send a team of experts to work with civil society networks and governments to help build technical expertise in tackling the threat of violent extremism.

"So understanding what is attracting young people, mostly young people, to extremist ideologies grappling with that and promoting a culture — which is very consistent of course with the culture of the Commonwealth — of mutual respect," Mr Turnbull said after the meeting.

Mr Turnbull said it was important to respond quickly to online threats because extremist ideology was "dynamically driven" through those means.

Commonwealth secretary-general Kamalesh Sharma said although the unit had only secured funding from two Commonwealth members, it gave "a very strong hint" for other states to do the same.

"Because this is a cause that is going to be before us for a very long time," he said.

Australia has reviewed its own counter-terrorism laws this year and implemented a number of measures to target the growing terror threat.