Nato countries: Which member states are in the military alliance
Finland joins the alliance on 4 April, bringing the total number of signatories to 31
Finland has completed the necessary steps to join North Atlantic Treaty Organisation (Nato), making it the organisation's 31st member.
After Russia's invasion of Ukraine last year, the Nordic nation and Sweden jointly asked to join the alliance.
Hungary and Turkey's objections have stalled Sweden's request.
Together with those of its allies, Finland's flag has now been raised.
Who are the member states that make up Nato?
In 1949, there were 12 founding members of the Alliance: Belgium, Canada, Denmark, France, Iceland, Italy, Luxembourg, the Netherlands, Norway, Portugal, the United Kingdom and the United States.
Since then, 19 more countries have joined the Alliance: Greece and Türkiye (1952); Germany (1955); Spain (1982); Czechia, Hungary and Poland (1999); Bulgaria, Estonia, Latvia, Lithuania, Romania, Slovakia and Slovenia (2004); Albania and Croatia (2009); Montenegro (2017); North Macedonia (2020); and Finland (2023).
Who is next?
Sweden was set to be the next member of the alliance, but due to political differences, Turkey and Hungary have resisted the move.
Despite not being a full member, Ukraine is regarded as a Nato "partner country." Though the war with Russia currently prevents it, it could eventually join the alliance.
Georgia, a partner nation that was invaded by Russia in 2008, has long wished to join as a full member.
Due to their commitment to neutrality under their constitutions, a number of other European countries, including Austria, Switzerland, and Ireland, are not a part of the alliance.
The Balkan countries Kosovo, Serbia, and Bosnia and Herzegovina do not belong to Nato.