in a major speech on the war in Ukraine, U.S. President Joe Biden has said that the conflict is a clear test for democracies around the world, and he portrayed the Ukrainian resistance against Russian forces as part of a “great battle for freedom.”

Speaking on March 26 at Warsaw’s Royal Castle, Biden said there was no justification for Russia’s brutal war of aggression in Ukraine and openly called for the removal of Russian President Vladimir Putin from office.

“For God’s sake this man cannot remain in power,” Biden said, concluding his speech, which came at the end of a three-day trip to Europe.

Earlier on March 26 while visiting Ukrainian refugees in Warsaw, Biden called Putin a “butcher” and in his speech referred to him as a tyrant.

Addressing a crowd of about 1,000 people later that evening, Biden reiterated that the United States stands with Ukraine, saying that Russia is trying to crush democracy inside Russia and endanger it in its neighbors.

Democracies around the world must prepare for a “long fight ahead” and all freedom-loving countries must commit to safeguarding democracy over the long haul, Biden said.

“It will not be easy. There will be costs,” he added.

The U.S. president repeatedly referred to Putin by name, blasting him for meeting Western attempts at “real diplomacy” prior to the conflict with “disinterest” and “lies.”

He also reiterated that Russia’s invasion has only served to strengthen NATO and the West, which he said is “more united” than ever.

As a result of the war, he said, there are more NATO soldiers in Eastern Europe, not less, as Russia had demanded, Biden said.