A large majority of lawmakers -- 182 votes for versus six against -- approved the accession of the Nordic country into the military alliance.

The vote means that 29 out of 30 NATO member state parliaments have ratified Finland's accession, with the last -- Turkey's assembly -- expected to also give Helsinki the nod next month.

"Thank you for the decision with clear numbers!" said Finnish Prime Minister Sanna Marin on Twitter after the vote.

NATO's expansion into Finland -- a country with a 1,340-kilometre (830-mile) border with Russia -- will roughly double the length of the bloc's current frontier with its Cold War-era foe.

Finland had initially aimed to join together with fellow NATO aspirant Sweden -- a Nordic power facing a litany of disputes with Turkey that ultimately sunk its chance to join the bloc before an alliance summit in Vilnius in July.

"The NATO membership of Finland and Sweden will strengthen the security of the whole Alliance," said Marin.

"It is in everyone's interest that Sweden also becomes a member of NATO before the Vilnius Summit," she said.

Helsinki and Stockholm ended decades of military non-alignment and decided to join the world's most powerful defence alliance in the wake of Russia's invasion of Ukraine.

Their applications were accepted at a June 2022 NATO summit but the bids still needed to be ratified by all alliance member parliaments -- a process that stalled once it reached Turkey and Hungary.

The nationalist Orban, who nursed close relations with Russian President Vladimir Putin until the invasion, said in December that the ratification process would begin in February.

Budapest insisted that it supports both Nordic nations' NATO accession but complained that they had unfairly criticised Hungarian government policy.

EU member Hungary is also in talks with Brussels to unlock billions of euros in bloc funding held up over rule-of-law and corruption concerns.

The Hungarian opposition accused Orban's party of trying to put pressure on the bloc by refusing to put the issue on parliament's agenda for a vote.

The Finland vote delay "served the interests of Putin", said an opposition party leader, Ferenc Gerencser, before Monday's vote.

Fidesz said it will decide about backing Sweden's admission to the military alliance at a later date.

Last week, Orban's chief-of-staff Gergely Gulyas told reporters the Swedish bid will likely be ratified during the ongoing parliamentary session which runs until June 15.

Turkish President Recep Tayyip Erdogan is calling for Stockholm to take tougher action against Kurdish activists Ankara considers "terrorists".