Finland will become the 31st member of the military alliance on 4 April, confirmed NATO Secretary-General Jens Stoltenberg on 3rd April.
The official flag-raising ceremony to add the Finnish flag to those of the other members will take place at NATO headquarters on Tuesday afternoon.
Turkey was the last of NATO's 30 members to accept Finland's application last month.
Finland which shares a border with Russia, applied to join the military alliance in the wake of Vladimir Putin's invasion of Ukraine last year.
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