Türkiye on Tuesday postponed NATO accession talks with Sweden and Finland after tensions have been escalating between Ankara and Stockholm due to the latter’s unchanging stance on supporting terrorists and anti-Türkiye propaganda.

Ankara announced its decision one day after President Recep Tayyip Erdoğan lashed out at Sweden for allowing weekend protests that included the burning of the Quran outside Ankara's Stockholm Embassy.

A Turkish diplomatic source said the tri-party meeting has been pushed back from February to a "later date," without providing any details.

The decision further diminished the chances of the two countries joining NATO before Türkiye’s May presidential and parliamentary elections.

Sweden's prime minister immediately called "for reflection, for calm in the process so that we can return to functioning talks between Sweden, Finland and Türkiye."

Ulf Kristersson said there were "provocateurs who wanted to spoil Sweden's relations with other countries" and foil its bid to join the U.S.-led Western military alliance.

"No national security question is more important than that we, with Finland, quickly become members of NATO," Kristersson said.

In the face of deteriorating ties between Ankara and Stockholm, Finland's Foreign Minister Pekka Haavisto on Tuesday for the first time floated the idea that it may have to consider joining the alliance alone while stressing that a joint accession remained the "first option."

"We have to assess the situation, whether something has happened that in the longer term would prevent Sweden from going ahead," Haavisto told broadcaster Yle.

Sweden's Foreign Minister Tobias Billstrom said he was "in contact with Finland to find out what this really means."

Türkiye has indicated that it has no major objections to Finland's entry into NATO.

Swedish leaders have roundly condemned the Quran burning but defended their country's broad definition of "free speech."

The incident came just weeks after PKK/YPG terrorist sympathizers hung an effigy of Erdoğan by the ankles in front of Stockholm City Hall, sparking outrage in Ankara.

Haavisto said the anti-Türkiye protests had "clearly put a brake on the progress" of the applications by Finland and Sweden.

"Those who allow such blasphemy in front of our embassy (in Stockholm) can no longer expect our support for their NATO membership," Erdoğan said in a speech after a Cabinet meeting on Monday.

"If you love members of terrorist organizations and enemies of Islam so much and protect them, then we advise you to seek their support for your countries’ security," he said.

The Quran burning was carried out by Rasmus Paludan, leader of the Danish far-right political party Hard Line. The stunt was a "disgrace," Erdoğan said.

Erdoğan said the burning of the Muslim holy book was a hate crime that could not be defended by free speech.

Meanwhile, the act in Sweden was protested across the world with Muslim countries announcing condemnations as well as criticism from the United Nations, United States and Germany.

A planned visit by the Swedish foreign minister and parliament speaker to Türkiye was canceled following the tensions.

Sweden and Finland, which shares a 1,300-kilometre (800-mile) border with Russia, decided jointly to end their decadeslong policies of military nonalignment, following Russia's invasion of Ukraine.

Their plans won formal support at a historic NATO summit in June, after which the two countries bids were ratified by 28 of NATO's 30 member states. Bids to join NATO must be ratified by all members of the alliance, of which Türkiye is a member.

Türkiye has frequently voiced that it does not oppose NATO enlargement, but rather criticizes Stockholm for not taking action against elements that are posing a security threat to Ankara.

Last June, Türkiye and the two Nordic countries signed a memorandum to address Ankara’s legitimate security concerns, paving the way for their eventual membership in the alliance.

But recent provocative demonstrations by terrorist group supporters and Islamophobic figures in Stockholm have led Turkish leaders to question Sweden’s commitment to take the steps necessary to gain NATO membership.

Ankara has long criticized Stockholm for housing members of various terrorist organizations, particularly members of the PKK and, in recent years, the Gülenist Terror Group (FETÖ) – the organization behind the 2016 defeated coup attempt in Türkiye.

Ahead of a historic NATO summit, the three countries signed a trilateral deal in June that prevented a Turkish veto. In the memorandum, the Nordic countries said they would address Türkiye’s extradition requests for terrorists. In addition, the joint directive states that Finland and Sweden "will not provide support to ... the organization described as FETÖ" and terrorist groups.