Finland's leaders say they are in favor of applying for NATO membership "without delay," apparently prompted by Russia's military offensive against Ukraine.
"NATO membership would strengthen Finland's security. As a member of NATO, Finland would strengthen the entire defense alliance," Finnish President Sauli Niinisto and Prime Minister Sanna Marin said in a joint statement on Thursday.
"Finland must apply for NATO membership without delay. We hope that the national steps still needed to make this decision will be taken rapidly within the next few days," the two leaders said.
Marin said the invasion of Ukraine had "changed everything" in terms of security for Finland.
Finland's Foreign Minister Pekka Haavisto, speaking at the European Parliament's foreign affairs committee around the time of the announcement, also said Russia's offensive against Ukraine had "altered European and Finnish security," but added that Finland was not facing "an immediate military threat."
The government will debate the issue over the weekend and the Finnish parliament is expected to give its final approval to the application as early as Monday.
The latest announcement signals a major shift in Finland's decades-long policy of military neutrality.
Soon after the announcement, Denmark said it would push for the quick admission of Finland into NATO. "Denmark will do everything for a quick admission process after the formal application," Prime Minister Mette Frederiksen said in a post on Twitter.
Meanwhile, neighboring Sweden is also expected to decide on joining NATO in the coming days.
Finland shares a 1,300-kilometer border with Russia. If it joins NATO, the land border that Russia shares with the Western military alliance's territories would roughly double.
In the wider Nordic region, Norway, Denmark, and the three Baltic states are already NATO members. If Finland and Sweden join NATO, it would likely anger Moscow, which says the Western military alliance's enlargement is a direct threat to its own security.
The war in Ukraine has apparently brought about a shift in public and political opinion in both Finland and Sweden over long-held policies of military non-alignment.
Former Russian President Dmitry Medvedev has already warned that Moscow would deploy nuclear weapons close to the Baltic states if Finland and Sweden joined the US-led NATO. Kremlin spokesman Dmitry Peskov has also said the possible accession of Sweden and Finland to the NATO military alliance would not bring stability to Europe.
Finland achieved independence from Russia in 1917 and fought two wars against it during the Second World War, losing some territory. Sweden, whose foreign policy has focused on supporting democracy and nuclear disarmament, has not fought a war for the last 200 years.