On Monday, Sweden's prime minister declared that Sweden would seek NATO membership alongside Finland in response to Russia's invasion of Ukraine, marking a historic reversal after more than two centuries of Nordic military neutrality.

The move, which is sure to anger the administration of Russian President Vladimir Putin, followed Finland's announcement on Sunday that it will also seek to join the 30-nation military alliance.

In her presentation to legislators in the Swedish capital, Prime Minister Magdalena Andersson referred to it as "a historic shift in our country's security policy."

"We will notify NATO of our desire to join the alliance," she stated. "Sweden requires the formal security assurances that come with NATO membership."

Andersson stated that Sweden was cooperating with Finland, whose government declared that it would seek membership in the alliance on Sunday.

The declaration was made on Monday after a debate in the Riksdagen, or parliament, revealed overwhelming support for joining NATO. Only two smaller left-leaning parties out of Sweden's eight parties opposed it.

On Sunday, the Swedish Social Democrats abandoned their long-held stance that Sweden must remain nonaligned, paving the path for a clear majority in parliament to support NATO membership.

Before the Russian invasion of Ukraine on February 24, public opinion in both Nordic countries was adamantly opposed to NATO membership. However, after the attack, support for NATO membership proliferated in both nations.

"The Swedish government intends to apply for NATO membership. A momentous day for Sweden," tweeted Swedish Foreign Minister Ann Linde. With broad support from political parties in the Swedish parliament, the conclusion is that Sweden will be more assertive with NATO allies.

Sweden had avoided military alliances since the end of the Napoleonic Wars when it was a regional power. Similar to Finland, it remained neutral throughout the Cold War but established tighter ties with NATO after the fall of the Soviet Union in 1991.

After the Russian invasion of Ukraine, the administrations of Finland and Sweden initiated discussions across political parties about NATO membership. They reached out to the United States, the United Kingdom, Germany, and other NATO nations for support.

However, the Kremlin has consistently warned that the action will destabilize Europe's security.

Monday, Russian President Vladimir Putin stated that Moscow "does not have a problem" with Sweden or Finland's NATO membership applications but that "the expansion of military infrastructure onto this territory will inevitably elicit a response from us."

Mitch McConnell, leader of the Senate Republicans, stated on Monday in Helsinki that there is "very significant" support in Congress and that he anticipates speedy passage. He expressed hope for a vote before the August recess.

Only the minor Left and Green parties opposed NATO membership in the Swedish Parliament.

Andersson stated that Sweden would reject nuclear weapons and permanent NATO bases on its territory, similar to Norway and Denmark's criteria when the alliance was created after World War II.

Though NATO officials have voiced anticipation for a quick ratification procedure, all 30 present NATO members must consent to Finland and Sweden's membership before they may be included. Turkey said reservations last week, accusing the two nations of aiding Kurdish insurgents and other individuals deemed terrorists by Turkey.

Peter Hultqvist, the Swedish minister of defense, informed SVT that a Swedish delegation would be dispatched to Ankara to discuss the matter.