US President Joe Biden on Saturday portrayed Ukraine's resistance against Russian forces as part of a "great battle for freedom" and said the world should prepare for a "long fight ahead".
Speaking at Warsaw's Royal Castle in Warsaw, Biden also said Russia "has strangled democracy and sought to do so elsewhere."
"We stand with you," Biden said in Warsaw, adding that Russia was trying to crush democracy in its own country and was also endangering its neighbours.
Biden has condemned Russian President Vladimir Putin's claim that Russia is engaged in "de-Nazification" in Ukraine.
"Putin has the gall to say that he is de-Nazifying Ukraine. It's a lie, it's just cynical, he knows that, it is also obscene," Biden said.
He said Ukrainian President Volodymyr Zelensky had been elected democratically, was Jewish and that his father had been a victim of the Holocaust, in comments made in Warsaw at the end of his two-day visit to Poland.
There was no justification for Russia's brutal war of aggression in Ukraine, Biden said at Warsaw's Royal Castle, a symbol of the Polish capital that was rebuilt after it was largely destroyed in World War II.
Biden also called the conflict in Ukraine a "strategic failure" for Russia but said ordinary Russians were "not our enemy".
"Let there be no doubt that this war has already been a strategic failure for Russia," Biden said in a speech at the Royal Castle in Warsaw. Moscow will never see victory in Ukraine, he added.
'You, the Russian people, are not our enemy," Biden said in Poland as he condemned Putin's invasion of Ukraine.
He warned that Russia will soon fall out of world's top 20 economies due to sanctions.
Biden warned Russia also not to move on an "inch" of NATO territory.
"Don't even think about moving on one single inch of NATO territory," Biden warned, reiterating the "sacred obligation" of alliance members to defend their territory "with the full force of our collective power."
Putin had miscalculated with the war of aggression in Ukraine, Biden said, adding that NATO and the West were now stronger and "more united" than ever.
Russia wanted fewer NATO soldiers in Eastern Europe; now there are more, he said. The US alone now has more than 100,000 troops in Europe, he said.
As he was ending his speech he called for Putin's removal, saying that he could not remain in power.
"For God's sake, this man cannot remain in power," Biden told a crowd in Warsaw. Biden also said the Russia-Ukraine war, now in its second month, had united the West, adding that NATO was a defensive alliance which never sought Russia's demise.
