A growing majority of Swedes are now in favour of joining Nato despite threats of retribution from Russia, new polling has revealed.
On Wednesday, research by Demoskop and commissioned by the Aftonbladet newspaper showed 57% of Swedes now favoured Nato membership, up from 51% in March.
Sweden, along with neighbouring Finland, has moved towards dropping decades of military neutrality in the face of Putin's bloody invasion of Ukraine.
The March poll was the first to show a majority of Swedes in favour of joining the alliance. In January, a month before the invasion, just 37% were in favour of Nato membership.
Prompted by Putin's attack on Ukraine, Sweden is currently in the midst of a review into its security policy, which will conclude at the end of May.
Some reports have suggested Sweden's prime minister Magdalena Andersson wants the country to join the transatlantic alliance by June.
Momentum has also been growing in Finland, which shares an 830-mile land border with Russia, with the country expected to apply for Nato membership at a similar time to Sweden.
On Wednesday, Finland inched closer to joining the alliance, after the country's major parliamentary groups all expressed support for some form of military alliance.
The move came during a debate in the Finnish parliament, discussing the possibility of Nato membership.
Prime minister Sanna Marin's Social Democrat party voiced support for a military alliance, but stopped short of directly mentioning Nato.
"It is evident that Russia's actions have brought Finland several steps closer to military alignment being necessary," Social Democrat group leader Antti Lindtman said.
Putin has spent decades viewing Nato as a threat, and Moscow has been clear that it opposes any chance for the alliance to get larger.
The Kremlin issued a fresh threat to Finland and Sweden on Wednesday.
Maria Zakharova, spokesman for Russia's foreign ministry, said both nations have been informed "what it will lead to" if they abandon their neutrality agreements.
"We have issued all our warnings both publicly and through bilateral channels," she told the Rossiya 24 state media channel.
"They know about it, they will have nothing to be surprised about, they were informed about everything."
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Finland has been officially neutral since signing a pact with Russia in 1948, agreeing to never join a military alliance hostile to Russia, or allowing its territory to be in an attack against Russia.
Nato secretary general Jens Stoltenberg said last week Nato allies would welcome Finland and Sweden into the alliance if they decided to join.
Kremlin spokesman Dmitry Peskov has previously said that joining the alliance would not bring any further security to Europe.
He said the bloc "is not that kind of alliance which ensures peace and stability, and its further expansion will not bring additional security to the European continent".
Sweden has not been at war since the time of Napoleon and has built its security policy on "non-participation in military alliances".
But like Finland, the invasion of Ukraine, which Moscow calls a "special military operation", has forced a radical rethink.
Both countries are now seen as highly likely to join the 30-nation alliance.
Putin's troops continued their assault on Eastern Ukraine on Wednesday, with fighting intensifying in the southeastern Donbas region.
Ukrainian forces clung on to the besieged city of Mariupol, where a Russian ultimatum to to surrender or die expired on Wednesday afternoon with no mass capitulation.
More than five million people have now fled Ukraine since the start of the conflict, the United Nations refugee agency said.