Ukraine's neighbors, including three Baltic nations, Bulgaria and Georgia, condemned Russia's invasion of the country on Thursday.
The foreign ministers of Baltic states Estonia, Latvia and Lithuania issued a joint statement condemning in the "strongest possible way the open large-scale Russian aggression against the independent, peaceful and democratic Ukraine."
Stressing that "this act of aggression is not acceptable," the statement said Russia's attack on Ukraine is a "blatant violation of the international law, of all international norms and a crime against Ukrainian people."
They urged the international community to impose the strongest possible sanctions on Moscow, including Russia's exclusion from the international payments communication system SWIFT.
Bulgarian President Rumen Radev and Prime Minister Kiril Petkov both condemned Russia's "absolutely unacceptable" military intervention in Ukraine.
At a joint news conference, Radev said his country's doors are open to Bulgarians in Ukraine and to Ukrainian citizens seeking asylum.
"We strongly condemn the actions of the Russian Federation. Bulgaria will take a joint stance with NATO against this unacceptable attempt," Petkov added.
Georgian President Salome Zurabishvili expressed support for Ukraine and called for a stop to Russian aggression.
"Georgian nation shocked by the Russian aggression in Ukraine. We stand in solidarity with the Ukrainian people and call for a halt of the military operations," she said on Twitter.
Russian President Vladimir Putin announced a military intervention in Ukraine early Thursday, just days after recognizing two separatist-held enclaves in eastern Ukraine, drawing widespread international condemnation and announcements of tougher sanctions on Moscow.
The intervention followed a month-long buildup of some 100,000 troops around Ukraine, with Russia repeatedly denying any intent to launch an invasion.
There were also reports on Thursday of explosions in several Ukrainian provinces, including the capital Kyiv, and several military vehicles reportedly crossed the border from Belarus into Ukraine.
Meanwhile, European Union chief Charles Michel urged Belarus to "not take part" in Russia's military assault on Ukraine, ahead of an emergency EU summit to decide new sanctions on Moscow over its invasion.
In an appeal to Belarus and its people during a media conference at NATO headquarters, Michel said: "You have the choice not to follow Russia's destructive action. You have the choice not to take part in this needless tragedy against your neighbors in Ukraine."
Belarus, a Russian ally that borders Ukraine to the north, has welcomed tens of thousands of Russian troops in its territory in the wake of mass pro-democracy protests that erupted in 2020 after autocratic leader Alexander Lukashenko claimed victory in skewed elections.
Belarus is permitting those troops to pour across its border into Ukraine and to use their positions to hammer Ukrainian forces with artillery, according to Ukraine's government.
Lukashenko on Thursday said that Putin had called him to inform him of his military operation against Ukraine. He said that Belarus's own national forces "are not taking part in this operation."