A Turkish court has convicted an Australian-born Islamic State militant of belonging to a terror group and sentenced him to more than seven years in prison.

Neil Prakash has been in a Turkish prison since 2016 when he was arrested near the Syrian border for attempting to cross with fake documents.

Delivering its verdict Friday, the court found Prakash guilty of IS membership and sentenced him to seven years and six months in prison. The court said he could be released in two-and-a-half years under Turkish law, however.

Prakash expressed remorse, telling the court: "I used to be a member of Daesh but I am no longer."

Australia has stripped Prakash of his citizenship. It has also requested his extradition.