(Brussels) After three decades of military non-alignment, Finland officially became NATO’s 31st member country on Tuesday, a “historic day” for the alliance that sparked Russia’s wrath.

“We declare Finland the 31st member of the Alliance with the receipt of these documents”, launched the head of the American diplomacy Antony Blinken, whose country is depositary of the North Atlantic treaty, during a brief ceremony at the headquarters of NATO in Brussels.

“It is of course a great day for Finland […] It is also a good thing for NATO,” Finnish Defense Minister Antti Kaikkonen said ahead of the ceremony.

The US Secretary of State, who was presented with the membership documents, and NATO chief Jens Stoltenberg hailed a “historic day”.

“I’m tempted to say that maybe that’s the only thing we can thank (Russian President Vladimir) Putin for, because he once again precipitated something that he said he wanted to avoid by attacking” Ukraine, commented Antony Blinken.

Moscow denounced an “attack” on its security and promised “countermeasures”.

The Nordic country, which shares a 1,300 kilometer long border with Russia, became the 31st member of the Alliance on the anniversary of its creation, April 4, 1949.

The Finnish flag was still to be hoisted in the main courtyard of the organization’s headquarters in Brussels at 3:30 p.m. (9:30 a.m. Eastern time), between those of Estonia and France, according to the alphabetical order.

“Finland is now safe,” said Jens Stoltenberg.

“Together, the NATO Allies represent 50% of the world’s military power. So as long as we stick together and protect each other and do so credibly, there will be no military attack on a NATO ally,” he explained.

By joining NATO, Finland, which was invaded by the Soviet Union in 1939, doubles the length of the border with Russia of the US-led alliance.

She gains the protection of Section 5, the Collective Defense Pledge that an attack on one member “shall be considered an attack on all members.”

Objections from Turkey and Hungary delayed Helsinki’s accession for months, and are still blocking Stockholm’s.

“I am absolutely confident that Sweden will also become a member. It is, for NATO, for me, a priority to ensure that this will happen as quickly as possible”, assured Jens Stoltenberg.

Sweden must join NATO “without delay” because with these 2 countries our Alliance will be stronger to ensure the security of the Euro-Atlantic area, said French Minister for Europe and Foreign Affairs Catherine Colonna.

“We hope that the Swedish flag will fly in NATO for the Vilnius summit,” commented his Lithuanian counterpart Gabrielus Landbsergis.

“I call on President Erdogan not to ruin the Vilnius summit,” he said.

Chance of the alphabetical order, the colors of Sweden would then be hoisted between those of Spain and Turkey.

The accessions of these two Nordic countries are the demonstration that “the door of NATO remains open”, hammered Jens Stoltenberg.

“NATO’s position remains unchanged: Ukraine will become a member of the Alliance,” he continued.

However, he added immediately, “the main objective at the moment is its survival as a sovereign and independent country, otherwise to speak of membership is meaningless”.

NATO Foreign Ministers will meet with their Ukrainian counterpart Dmytro Kouleba and will discuss “long-term support” in Kyiv.

“Ukraine is aiming for the same goal as Finland in becoming a full member of NATO, and our conversations here in Brussels will focus on how we can move forward,” the Ukrainian minister said upon arrival .

A meeting of the NATO-Ukraine Commission was organized for this purpose, despite the objections of Hungary.

During the night from Monday to Tuesday, Russian drones hit the Ukrainian port of Odessa, on the Black Sea, causing material damage, according to the authorities.

The ministers are also due to meet with their Japanese counterpart to discuss the situation in the Asia-Pacific region and the challenges posed by China and “its alignment with Russia”.

“To meet all these challenges, it is essential that we invest more in defence,” insisted Jens Stoltenberg.

“I expect allies to commit at the Vilnius summit in July to an ambitious new investment pledge, with 2% of their GDP as the floor and no longer as the ceiling.”