Sweden's Foreign Minister Ann Linde on Tuesday morning signed an application declaring the country wants to join NATO.

The move marks a formal step by Stockholm toward joining the US-led military alliance — ending decades of military neutrality — as Russia’s invasion of Ukraine sparks a dramatic evolution in European security and geopolitics.

“It feels very big, very serious, and it feels like we have arrived at a conclusion which is the best for Sweden,” Linde said. “We don’t know how long it will take, but we calculate that it could take up to a year.

“Now this week, this application will be submitted, together with Finland, in a day or so, and then it will be processed by NATO.”

Sweden’s Prime Minister Magdalena Andersson said Monday that the country should join NATO together with neighboring Finland to “ensure the safety of Swedish people.”

Russian President Vladimir President Putin said the entry of the two Nordic countries into NATO will not create a threat to Russia, but military expansion into the territory will “certainly cause our response.”