Finland joined NATO as the 31st Ally, depositing its instrument of accession in Brussels
Background
Finland became a NATO member on 4 April 2023, joining as the 31st Ally. It did so by depositing its instrument of accession to the North Atlantic Treaty with the United States at NATO Headquarters in Brussels. Finland is a member of the European Union. Its capital is Helsinki, its currency is the euro and its official languages are Finnish and Swedish. Its Parliament is the Eduskunta.
In plain words
NATO North Atlantic Treaty Organization — The collective defence alliance founded by the North Atlantic Treaty of 1949.
Eduskunta Parliament of Finland — Finland's unicameral legislature.
Instrument of accession Instrument of accession — The formal document a state deposits to become a party to a treaty.