Sweden's Prime Minister Ulf Kristersson. (Photo: Internet)

Finland and Sweden signed a three-way agreement with Turkey last year aimed at overcoming Ankara's objections to their membership of the North Atlantic Treaty Organization.

They applied in May to join NATO following the Russia-Ukraine but Turkey objected and accused the countries of harbouring militants, including from the outlawed Kurdistan Workers' Party.

At a news conference later on Sunday, Kristersson said the demands that Sweden could not or did not want to fulfil were outside the scope of the three-way memorandum.

Ankara expressed disappointment with a decision late last year from Sweden's top court to stop a request to extradite a journalist with alleged links to Islamic scholar Fetullah Gulen, blamed by Turkey for an attempted coup.