Finland officially became the 31st member of the North Atlantic Treaty Organization (NATO) on Tuesday, marking a major shift in the security landscape in northeastern Europe that adds some 1,300 kilometers (830 miles) to the alliance’s frontier with Russia.
The Nordic nation’s accession was sealed during a formal ceremony at the NATO headquarters in Brussels on Tuesday.
US Secretary of State Antony Blinken and NATO Secretary General Jens Stoltenberg were on hand as the Minister for Foreign Affairs, Pekka Haavisto, established Finland’s accession.
“Finland has today become a member of the defense alliance NATO. The era of military non-alignment in our history has come to an end. A new era begins,” the Finnish presidency said in a statement.
“Each country maximizes its own security. So does Finland. At the same time, NATO membership strengthens our international position and room for maneuver. As a partner, we have long actively participated in NATO activities. In the future, Finland will make a contribution to NATO’s collective deterrence and defense,” it added.

Finland’s acceptance into the US-led security alliance presents a blow to Russian President Vladimir Putin, who has long sought to undermine NATO, and before invading Ukraine, demanded the bloc refrain from further expansion.
The invasion instead drove non-aligned Finland and Sweden to abandon their neutrality and seek protection within NATO, though Sweden’s attempt to join the bloc has been stalled by alliance members Turkey and Hungary.
On the eve of Tuesday’s ceremony, NATO Secretary General Jens Stoltenberg heralded the raising of the Finnish flag for the first time at the alliance’s headquarters in Belgium, saying “it will be a good day for Finland’s security, for Nordic security, and for NATO as a whole.”