The Nordic nation said Turkey had asked Finland to reassess six previously rejected extradition requests.

"According to the Turkish request, they concern different crimes related to terrorism," Sonja Varpasuo, a senior specialist at the ministry told AFP.

Finland and Sweden announced plans to join NATO after Russia invaded Ukraine in February, ending long-standing policies.

Only Turkey has opposed their applications, demanding concessions from Helsinki and Stockholm in return for approval.

A deal was struck between the three countries in June, which included provisions on extraditions and sharing information, clearing the way for NATO to formally invite the Nordic nations to join the alliance.

However Ankara has insisted it could still block entry into the Western alliance -- which requires ratification by all NATO member states -- if it feels Sweden and Finland fail to deliver on their promises.

The requests to re-evaluate the Finnish decisions came in August, the ministry said, adding that Turkey had also submitted a new extradition request and that it had another already pending.

Varpasuo also said the decisions already made were final and "Turkey had been told that the cases cannot be reassessed".

"Decisions made by the Ministry of Justice based on the Act on Extradition cannot be appealed," Varpasuo said, adding that the only exception was in the case of a completely new report from Turkey, which it had not presented for any of the cases.

The three countries met in August for the first time since the Madrid deal to discuss Ankara's conditions for accepting the applications.

"Finland and Sweden have renewed their commitment to demonstrate full solidarity and cooperation with Turkey in the fight against all forms and manifestations of terror," Erdogan's foreign policy adviser Ibrahim Kalin's office said in a statement after the meeting.

In early August, Sweden announced the first extradition of a Turkish citizen after the agreement, but Turkey's justice minister later said that the extradition fell far short of Stockholm's commitments under the deal.