Russia has stated that it will be compelled to take "retaliatory measures" in response to Finland's decision to join NATO. According to a statement from the foreign ministry, the decision would gravely harm bilateral relations as well as northern European security and stability. Finland's president and prime minister have previously urged the country to seek for Nato membership "as soon as possible."

        Following Russia's invasion of Ukraine, popular support for Nato membership has risen dramatically. Finland and Russia have a 1,300-kilometer (810-mile) border. To avoid antagonizing its eastern neighbor, it has kept out of Nato until now.

        After consideration by parliament and other key political officials, Finland will publicly announce its choice on Sunday. Sweden has stated that it will make a similar announcement on the same day. Jens Stoltenberg, the Secretary General of NATO, has stated that he expects Sweden and Finland to join "very rapidly."

        The White House stated that if both countries applied to join NATO, the US would support them. Are Finland and Sweden considering joining NATO? What is NATO, and do Finland and Sweden have a chance to join? Is NATO's expansion into the Nordics a threat or a benefit to Europe?

        Finland's action was termed as "a major departure in the country's foreign policy" by a Russian statement (in Russian). "Finland's membership in NATO will have a significant negative impact on bilateral Russian-Finnish ties as well as the maintenance of peace and security in Northern Europe," it stated.

        "Russia will be obliged to take punitive measures, both military-technical and otherwise, to counter the challenges to its national security that this poses." Moscow, on the other hand, has not stated what actions it intends to take.

        According to Russian news agency Ria, Russia's deputy UN envoy Dmitry Polyansky indicated that if Sweden and Finland join Nato, they may become targets for Russia. Russian officials were reacting to a joint statement by Finnish President Sauli Niinisto and Prime Minister Sanna Marin, in which the two leaders stated they expected a Nato membership decision in the coming days.

        It stated that joining NATO would boost Finland's security. "Finland's membership in Nato would boost the whole defense alliance. Finland should ask for NATO membership as soon as possible." Later, in an interview with journalists, Mr Niinisto addressed Russian worries and blamed the action on Moscow's invasion.

        "Anyone would not be against joining NATO. This was your fault. Examine yourself in the mirror "he added. Last week, a survey found that 76 percent of Finns support joining NATO, with only 12 percent opposed, marking a significant shift toward participation since the invasion.

        During World War II, Finland and the Soviet Union were on opposite sides, with the Finns famously repelling a Soviet invasion in 1939-40. However, Finland lost 10% of its land in the final peace accord and remained a non-aligned country during the Cold War. Russia's boundaries with Nato would be more than doubled if it joined the organization. Sweden shares no borders with Russia.