"Our only expectation from NATO allies is... to first understand our sensitivity, respect and finally support it," Erdogan told his party's lawmakers in parliament.

Finland and Sweden on Wednesday submitted a joint application to join NATO as Russia's invasion of Ukraine forces a dramatic reappraisal of security in Europe.

Erdogan accused Stockholm of providing safe haven to members of the outlawed Kurdistan Workers' Party (PKK) designated as a terror group by Ankara and its Western allies.

"We asked them to extradite 30 terrorists but they refused to do so," he said.

"You will not send back the terrorists to us and then ask our support for your NATO membership .... We cannot say 'yes' to making this security organisation less secure," he added.

Sweden has also imposed embargoes on arms sales to Turkey since 2019 over Ankara's invasion of Syria.

"We are sensitive about protecting our borders against attacks from terror organisations," said Erdogan, calling on NATO allies to support Turkey's "legitimate" Syria operations or at least not to stand in their way.

The Turkish leader also said he was not warm to Swedish or Finnish delegations' request to visit Ankara for consultations.

"They want to come on Monday. They shouldn't bother. There's no need," he said.

Later Wednesday, Turkish presidential spokesman Ibrahim Kalin had a series of telephone conversations with advisers to the heads of state and foreign ministries of Germany, Sweden, Finland, the United Kingdom and the United States, according to the Turkish presidency.

During these talks, Kalin indicated that Turkey was waiting for "concrete steps" to address its concerns about its national security".

In the event of "non-fulfilment of Turkey's expectations", the accession process of the two Nordic countries "cannot move forward," Kalin added.

"Sweden's membership in NATO cannot be done until Turkey's well-founded concerns are dispelled. If you want NATO's second army to defend you in the event of aggression, you must accept this reality," Turkish presidency director of communications Fahrettin Altun said in an opinion piece published on Wednesday in the Swedish daily Expressen.