Finland's President Sauli Niinisto signed into law approving his country's NATO membership Thursday.

Parliament had voted by a large majority in early March in favor of the government's proposal on the legislation needed for the country to join the Western defense alliance. Niinisto had announced after the vote that he wanted to sign off on it before the Finnish parliamentary elections on April 2.

Finland, however, still has to wait for Türkiye and Hungary to ratify its membership application. All 28 other NATO members have already approved the accession.

Hungary aims to ratify Finland's accession on March 27. The Turkish Parliament's Foreign Affairs Committee approved it on Thursday but the General Assembly still has to approve it.

Against the backdrop of the Russian war in Ukraine, the Nordic country applied for membership in NATO last May together with Sweden.

The two countries had long hoped to join NATO at the same time but because of Türkiye's opposition to Sweden's accession, Finland could go ahead alone.

Finland shares a border with Russia that spans over 1,300 kilometers (807.7 miles).

NATO, in the meantime, announced that it is continuing the military integration process of the two countries, though the application process is not finalized. The alliance's Secretary-General Jens Stoltenberg told reporters in Brussels Tuesday that he was "absolutely confident," that Sweden would also become a full member of NATO.

"I really believe that it will be good for NATO," Stoltenberg said. "It will be good for Finland, it will be good for Sweden, it will be good for all of us to have Finland and Sweden in as quickly as possible. That is also the reason I worked hard to agree last year, which was a historic decision that all NATO Allies, also Türkiye and Hungary made to invite Finland and Sweden. And since then, since June last year, we had the quickest accession process in NATO's modern history because we remember that Finland and Sweden applied in May. In June, they were already invited," he added.