Russia has told Finland and Sweden that their decision to join the Nato military alliance is a serious mistake with far-reaching consequences and that they should not assume that Moscow will not respond.
The Finnish government on Sunday confirmed its intention to join Nato while Sweden’s ruling party agreed to drop its longstanding opposition to the idea, paving the way for a joint membership application within days.
The decisions by the two governments, both of which have remained neutral or non-aligned since the end of the second world war, herald a historic redrawing of Europe’s security map prompted by Russia’s invasion of Ukraine on 24 February.
“The situation is, of course, changing radically in light of what is happening,” Russia’s deputy foreign minister, Sergei Ryabkov, said on Monday. “The fact that Finland and Sweden’s security will not be strengthened as a result of this is very clear to us.”
Ryabkov added that the two Nordic nations “should have no illusions that we will simply put up with it”, warning that the move was “another grave mistake with far-reaching consequences” and the “general level of military tension will increase”.
The Kremlin spokesperson, Dmitry Peskov, also said on Monday that Moscow would “follow very carefully what will be the consequences” of the Nordic nations’ move “for our security, which must be ensured in an absolutely unconditional manner”.
Russia has repeatedly warned both countries against joining Nato, saying such a move would oblige it to “restore military balance” by strengthening its defences in the Baltic Sea region, including by deploying nuclear weapons.
Finland shares an 810-mile (1,300km) land border with Russia and Sweden a maritime border. Both countries have for decades considered that joining the 30-member, US-led Nato alliance would represent an unnecessary provocation of Moscow.
However, Putin’s invasion of Ukraine on 24 February has led to a profound change in Nordic thinking, with public support for Nato accession in Finland more than trebling to about 75% and rising to between 50% and 60% in Sweden.
The Swedish and Finnish parliaments on Monday began debating the issue, with the session in Helsinki likely to last several days. While 85% of Finland’s 200 MPs back membership, 150 have requested to speak and a vote was not expected on Monday.
“Our security environment has fundamentally changed,” the prime minister, Sanna Marin, told parliament as she opened the debate on Monday. “The only country that threatens European security, and is now openly waging a war of aggression, is Russia.”
In Stockholm, where the parliamentary vote was also expected to be a formality, the prime minister, Magdalena Andersson, told MPs “a historic change in our country’s security policy” was underway and that Sweden “needs the formal security guarantees that come with Nato membership”.
She added: “Unfortunately, we have no reason to believe the current trend [of Russia’s actions] will be reversed in the foreseeable future.” A formal Swedish government decision to join the alliance is expected later on Monday.
The Finnish president, Sauli Niinistö, is due in Stockholm on an official visit on Tuesday and Wednesday, suggesting a joint application by the two Nordic neighbours to join the alliance could be formally submitted within the next three days.
The Nato secretary general, Jens Stoltenberg, has said the countries would be “welcomed with open arms” and their accession would be quick, although Turkish objections could delay the process, which requires unanimity among members.
Sweden’s defence minister, Peter Hultqvist, said on Monday Stockholm was working to overcome Ankara’s reservations, which centre on Swedish support for the Kurdish PKK group, designated a terrorist organisation by Turkey, the EU and the US.
“We will send a group of diplomats to hold discussions and have a dialogue with Turkey so we can see how this can be resolved and what this is really about,” Hultqvist said.
Speaking before a meeting with EU foreign ministers in Brussels, the Canadian foreign minister, Mélanie Joly, called for Finland and Sweden’s speedy accession.
“Our goal is to be amongst the first countries to be able to ratify the accession of Sweden and Finland, because we know that the interim period between the accession demand and the ratification must be shortened,” she said.
Joly added that she had held discussions with Turkey, saying: “We need to meet this moment, this is historic and it is way more important than any bilateral issues.”
Nato and the US have both said they were confident Turkey would not hold up the Sweden’s accession. “I’m confident we will be able to address the concerns Turkey has expressed in a way that doesn’t delay the membership,” Stoltenberg said on Sunday.