Finland became an official member of NATO as of Tuesday afternoon, in response to the conflict in Ukraine.

In a ceremony held outside the Alliance’s headquarters in Brussels, Finland’s blue and white flag was raised among those of its partners – after the exchange of relevant documents – with the Nordic country thus becoming the 31st member.

US Secretary of State Anthony Blinken spoke of a “historic day” for NATO, referring to Finland’s accession.

“I’m tempted to say that maybe that’s the only thing we can thank Russian President Putin for because he caused something that he clearly wanted to prevent,” said Anthony Blinken, adding: “This is truly a historic moment for the Alliance, for the Transatlantic Community but also for the world community that strongly defends the basic principles of the UN Charter and strongly defends the security and stability of peace. This is truly a historic day because today we welcome Finland to the Alliance.”

For his part, the President of Finland Sauli Niinisto said that “Finland became a member of the NATO alliance today. The era when the country was militarily non-committal has come to an end. A new era begins. Each country maximizes its own security. Finland does the same. At the same time, joining NATO strengthens our international position and room for maneuvering. As a partner, we have been actively involved in NATO activities for a long time. In the future, Finland will contribute to NATO’s collective deterrence and defense. Finland’s accession to the Alliance does not target anyone. Nor does it change the foundations or goals of Finland’s foreign and security policy.”

The NATO enlargement, with the addition of Finland, coincides with the 74th anniversary of the signing of the founding Washington Treaty on April 4, 1949. Moreover, this is the first NATO enlargement since North Macedonia joined the alliance in 2020.

The Kremlin said earlier that it could be forced to take “countermeasures” to ensure the security of its borders.

Finland, which applied to join NATO in May 2022, shares a 1,340-kilometer (832-mile) border with Russia.

This move is a strategic and political blow to Russian President Vladimir Putin, who has long complained about NATO’s expansion close to Russian borders.

Kremlin spokesman Dmitry Peskov called Helsinki’s move to join the bloc an “encroachment” on Russia’s security and said the NATO structure is hostile to Russia.