Officials in the traditionally neutral Nordic nations of Sweden and Finland confirmed Monday that the countries will simultaneously apply to join the North Atlantic Treaty Organization amid increased public support for the move as Russia continues its brutal invasion of Ukraine.

Two newspapers—Finland’s Iltalehti and Sweden’s Expressen—reported that the countries’ applications could occur as soon as the middle of next month. The Swedish daily Aftonbladet reported that Sweden has received concrete promises from the United States and the United Kingdom regarding protection and political support during the NATO application process.

According to The Guardian:

Finland’s prime minister, Sanna Marin, said then that her country, which shares a 1,300km (810 mile) border with Russia, would decide whether to apply to join the alliance “quite fast, in weeks not months,” despite the risk of infuriating Moscow.

Her Swedish counterpart, Magdalena Andersson, said Sweden had to be “prepared for all kinds of actions from Russia” and that “everything had changed” when Moscow attacked Ukraine.

As recently as last month, the center-left Andersson rejected opposition calls to join NATO, saying that doing so would “further destabilize this area of Europe and increase tensions.”

According to recent polling, just over half of Swedes and more than six in 10 Finns support their respective countries joining NATO.

However, peace activists in both countries have spoken out against NATO membership, with Agnes Hellström of the Swedish Peace and Arbitration Society saying “we don’t think it would make us safer or the world more secure.”

“It would make us part of a nuclear doctrine, and our possibility to be a voice for democracy, prevention, and disarmament would decrease,” she told Democracy Now! earlier this month.

Anti-war activists and experts have long argued that NATO enlargement—and especially its expansion into former Soviet and Warsaw Pact nations—is highly provocative toward Russia. Moscow has warned that further NATO expansion would force Russia to bolster its military capabilities—including by deploying more nuclear weapons—along its borders with alliance members.