"Our position on Finland is positive, but it is not positive on Sweden," Erdogan said of their NATO applications in a speech to his AK Party deputies in parliament.

Sweden and Finland applied last year to join the trans-Atlantic defence pact after Russia invaded Ukraine, but faced unexpected objections from Turkey and have since sought to win its support.

Ankara wants Helsinki and Stockholm in particular to take a tougher line against the Kurdistan Workers' Party (PKK), which is considered a terror group by Turkey and the European Union, and another group it blames for a 2016 coup attempt.

The three nations reached an agreement on a way forward in Madrid last June, but Ankara suspended talks last month as tensions rose following protests in Stockholm in which a far-right Danish politician burned a copy of the Muslim holy book, the Koran.

"Sweden should not bother to try at this point. We will not say 'yes' to their NATO application as long as they allow burning of the Koran," Erdogan said.

Sweden's Foreign Minister said there could be no compromise over freedom of speech, but that Sweden would continue to implement the Madrid agreement.

"It is very clear what is necessary for Sweden to become a member of NATO and that is that we meet the requirements which are present in the trilateral agreement," he told national news agency TT.

"Religion is not part of the agreement."

At the weekend, Erdogan signalled that Ankara could agree to Finland joining NATO ahead of Sweden. But Finland's Foreign Minister Pekka Haavisto said on Monday his country was sticking to its plan to apply jointly with Sweden.

Of NATO's 30 members, only Turkey and Hungary are yet to ratify the Nordic countries' memberships.

Asked whether Turkey had plans for separate processes for Finland and Sweden, Turkish Foreign Minister Mevlut Cavusoglu said it was NATO and the two Nordic countries who would decide on any separate ratifications.

"If NATO and the two countries decide for separate membership processes, Turkey will of course reconsider Finland's membership separately and more favourably," Cavusoglu said at a news conference with his Estonian counterpart in Tallinn.

Finland on Wednesday repeated its position that it will move in step with its Nordic neighbour.

"Finland continues to advance the membership process together with Sweden," the joint presidential and government committee on Finnish security and foreign policy said in a statement.

"The fastest possible realisation of both countries memberships is in the best interest of Finland, Sweden and the whole NATO," it added.