Turkey’s Erdogan endorses Finland’s NATO bid.

Two leaders holding umbrellas in the rain while flanked on either side in a ceremony.
President Recep Tayyip Erdogan, left, and Finland’s president, Sauli Niinisto, in Ankara, Turkey, on Friday.Credit...Murat Cetinmuhurdar/Presidential Press Office, via Reuters

Turkey announced on Friday that it would move to ratify Finland’s application to join NATO, clearing a significant hurdle for the Nordic nation’s bid to join the alliance but leaving neighboring Sweden on the sidelines for now.

“We decided to start the ratification process in our Parliament for Finland’s membership,” President Recep Tayyip Erdogan of Turkey told a news conference, saying he hoped the vote would take place before elections in mid-May.

The announcement came as Finland’s president, Sauli Niinisto, met in Ankara with Mr. Erdogan. The leaders had both telegraphed that the announcement was coming, with Mr. Erdogan saying this week that Turkey would “keep our promise.”

For Finland to join NATO after decades of military nonalignment would be a major shift in the balance of power in the region between the Western military alliance and Russia. It represents a significant diplomatic and strategic defeat for Moscow and President Vladimir V. Putin of Russia.

Mr. Putin made clear before invading Ukraine last year that his intention was to block NATO’s expansion. But his invasion instead convinced Finnish and Swedish leaders that there was no real security guarantee for them outside the alliance.

Finland has a border of some 830 miles with Russia, the longest border with the country of any European Union nation, and an extensive history of resisting Moscow’s hegemony. Favoring self-reliance, Finland did not shrink its military after the collapse of the Soviet Union, and 10 months ago it pulled a more reluctant Sweden along to apply to join NATO.

But Mr. Erdogan has been blocking them, claiming that Sweden has become a haven for Kurdish separatists and other dissidents he considers terrorists. So far, Stockholm’s efforts to satisfy him, including a new terrorism law, have failed.

The Turkish president has intermittently demanded the extradition of more than 120 people now in Sweden, as he did again on Friday. Talks will likely continue in the hope that Turkey will finally approve Sweden’s membership bid after the Turkish elections in May, but before NATO’s summit meeting in Lithuania in mid-July.

Mr. Erdogan’s decision opens the way for Turkey’s Parliament to ratify Finland’s membership in the alliance, which requires unanimous approval from the 30 nations in the bloc. Hungary is the only other country whose Parliament has not ratified the bids by Finland or Sweden. Its leader, Prime Minister Viktor Orban, has vacillated on when the Hungarian Parliament will vote, although he insists that Hungary has no objection to membership of either Nordic country.

With elections in Finland on April 2, the country’s current government decided to pass all necessary legislation to join NATO in order to prevent any period of uncertainty while a new government is formed. So the only votes outstanding rest with the Turkish and Hungarian Parliaments.

On Friday, Mr. Niinisto thanked Mr. Erdogan for the move to ratify but told the news conference that Finland’s membership “is not complete without Sweden.”

The Turkish leader faces a tough election battle in mid-May with a ropy economy and high inflation, as well as criticism about his government’s handling of the recent devastating earthquake. The battle against Kurdish terrorism is popular politics in Turkey and plays well among opposition voters, too. And Turks in general like the attention and leverage that Mr. Erdogan’s unpredictability often provides.

Hungary has wielded its veto power within the European Union over sanctions against Russia to try to secure concessions on other issues, and analysts say Mr. Orban appears to be doing the same thing over Finland and Sweden joining NATO. Mr. Orban is also known to be annoyed by criticism of Hungary within the European Union from Sweden and Finland.

Johanna Lemola, Gulsin Harman and Anushka Patil contributed reporting.