Finland has officially been named the 31st member of NATO, 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.

“Finland has today become a member of the defence 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 manoeuvre. 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 defence,” it added.

US Secretary of State Antony Blinken, NATO Secretary General Jens Stoltenberg were on hand at NATO’s Brussels headquarters as Finland's Foreign Minister Pekka Haavisto deposited the country's instrument of accession.

Their flag will be raised outside NATO headquarters on Tuesday afternoon in a ceremony attended by NATO foreign ministers, including Blinken. For all future NATO meetings, Finland participates as an Ally — seated at the table between Estonia and France.

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 country’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.