Sweden’s bid to join the North Atlantic Treaty Organization (NATO) hit its latest roadblock on Monday.

Russian President Vladimir Putin‘s invasion of Ukraine last February prompted Sweden and Finland to begin efforts to join NATO, a military alliance of European and North American countries. Both countries would need unanimous support from the current NATO member states to gain entry, but Turkey has raised concerns over what it views as their lax attitude toward Kurdistan Workers’ Party (PKK) militants, which Turkey views as a terrorist organization.

Tensions between Turkey and Sweden have grown in recent weeks amid far-right and Kurdish protests in Stockholm. One protest, in which a far-right politician burned a Quran, the holy book of Islam, sparked strong rebuke from Turkey.

On Monday, Turkish President Tayyip Erdogan threatened to derail Sweden’s NATO membership bid over the incident.

Sweden's NATO membership hits roadblock
Above, an image of Turkish President Recep Tayyip Erdogan and a NATO flag. Erdogan on Monday threatened to block Sweden’s bid to join NATO after a right-wing Swedish politician burned a Quran at a recent protest, sparking anger from many Muslim nations.
ADEM ALTAN/AFP via Getty Images;action press-Pool/Getty Images

“Those who allow such blasphemy in front of our embassy can no longer expect our support for their NATO membership,” Erdogan said on Monday, according to Reuters.

He added: “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.”

According to the Associated Press, Erdogan said Swedish NATO membership is “not happening.”

U.S. State Department spokesperson Ned Price told Reuters that “this is a decision and consensus that Finland and Sweden are going to have to reach with Turkey.” Still, it did not state whether U.S. authorities believe the dispute will result in Sweden permanently being blocked from the alliance.

It remained unknown whether the incident would affect Finland’s membership.

Turkey, Sweden and Finland appeared to make some inroads in the months prior to the latest protest. In June, they agreed to a deal that would have cleared the way for their membership.

The deal addressed Erdogan’s security concerns, pledging “unwavering solidarity and cooperation in the fight against terrorism, in all its forms and manifestations, which constitutes a direct threat to the national security of Allies as well as to international peace and security.”

Erdogan Delivers Victory for Anti-NATO Putin

Vladimir Putin would be one beneficiary of Sweden’s NATO membership being blocked.

Putin has advocated against the coalition’s expansion, which he views as encroaching on Moscow’s influence amid former Soviet republics and Eastern Europe. In the months leading up to the Ukraine invasion, Putin condemned the possibility of Ukraine joining the coalition.

However, Ukraine’s membership does not currently have the support of NATO member states including the United States, which has raised concerns about political corruption in Kyiv.

Moscow has threatened retaliation if Sweden and Finland were to join NATO. Putin has also said “the expansion of military infrastructure into this territory would certainly provoke our response.”

Newsweek reached out to Sweden’s Ministry of Foreign Affairs for comment.

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