Finnish Foreign Minister Pekka Haavisto on Tuesday handed over the document on the country's accession to NATO, making it the 31 member of the alliance.
According to the North Atlantic Treaty, the documents on the accession of new members are stored in the United States.
Finland's membership in NATO is not targeted against anyone, the presidential office said on Tuesday.
"Finland’s membership is not targeted against anyone. Nor does it change the foundations or objectives of Finland’s foreign and security policy. Finland is a stable and predictable Nordic country that seeks peaceful resolution of disputes," the office said in a statement.
