Strong borders key to multiculturalism: PM

Malcolm Turnbull has told a German forum that strong border control is key to maintaining public confidence in immigration.

He was asked about Australia's approach to multiculturalism, after Germany threw open its borders in 2015 to accept more than one million Syrian refugees.

The Prime Minister said he was careful not to give advice to other countries, but Australia was the most successful multicultural country on earth.

"Migration programs and multicultural society needs to have a commitment and an understanding, and the trust of the people," Mr Turnbull told the Konrad Adenauer Stiftung on Monday.

"Being in control of your borders is absolutely critical.

"You have to be able to exert your sovereign right to control your own borders."

Mr Turnbull said Australia went to great lengths to ensure migrants were settled and the migration program was carefully managed.

More than a quarter of Australians were born overseas and half have at least one parent born internationally.