Turkey's general assembly, where President Recep Tayyip Erdogan's ruling alliance holds a majority, voted 287-55 to approve the application that Sweden first made in 2022 to bolster its security in response to Russia's full-scale invasion of Ukraine.

Sweden's accession requires the formal approval of all 31 member states, including Hungary, but approval by Turkey was widely considered the biggest remaining hurdle to overcome.

Hungarian Prime Minister Viktor Orban, who has friendly relations with Russian President Vladimir Putin despite Moscow's war in Ukraine, said on Wednesday he would urge lawmakers to approve Sweden's accession at the first possible opportunity.

Parliament is not currently in session. The opposition Socialist party said last week it would call for an extraordinary session to approve Sweden's NATO entry bid, stranded in the Hungarian legislature since mid-2022 despite repeated pledges by Orban to support it.

"I do not doubt that one of the opposition parties -- who have consistently gone against Hungarian interests -- will call for the (extraordinary) meeting, but this will likely fail," Laszlo Kover, a founding member of Orban's ruling Fidesz, told news website index.hu.

"I do not feel any particular urgency. Moreover, I do not think there is an extraordinary situation."

On Wednesday, NATO Secretary-General Jens Stoltenberg urged Orban to ratify Sweden's NATO accession.

Despite Orban holding an iron grip on Fidesz, government ministers have repeatedly blamed the delays on grievances about Sweden's bid among ruling party lawmakers, hardly any of whom have ever rebelled against Orban.