President Joe Biden on Wednesday lauded Turkey for lifting its veto over Finland's and Sweden's bid to join NATO.

"I want to particularly thank you for what you did putting together the situation with regard to Finland and Sweden, and all the incredible work you're doing to try to get the grain out of Ukraine," Biden told Turkish President Recep Tayyip Erdoğan on the sidelines of a major NATO summit in Madrid. "You're doing a great job."

NATO could not move forward on Sweden and Finland's accession without Turkish approval.

Turkey was granted major concessions as part of the agreement, including Biden authorizing his officials to say they were willing to help in the modernization of the Turkish air force.

Additionally, Finnish and Swedish leaders promised not to support the Kurdish PKK or the Syrian YPG groups or any supporters of Gülen.

"I'm pleased to announce that we now have an agreement that paves the way for Finland and Sweden to join NATO," NATO Secretary-General Jens Stoltenberg said Tuesday evening. "Turkey, Finland, and Sweden have signed a memorandum that addresses Turkey's concerns, including around arms exports, and the fight against terrorism."

The NATO expansion could be one of the most significant of the alliance in decades.

Russian President Vladimir Putin had pushed for Sweden and Finland to not be accepted into NATO after both countries dropped their tradition of neutrality following Moscow's invasion of Ukraine in February.

Putin had justified the Ukraine invasion as a warning against NATO's expansion and said it was a threat to his country's security.

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