President Joe Biden delivered a forceful denunciation of Vladimir V. Putin’s invasion of Ukraine on Saturday, declaring “for God’s sake, this man cannot remain in power” and casting the military clash in Europe as the “test of all time” in a decades-long battle to defend democracy.

In a speech from a castle that served for centuries as a home for Polish monarchs, Biden described the face-off with Putin as a moment he has long warned about: a clash of competing global ideologies, of liberty versus oppression.

Russia’s choice to wage war without justification or provocation was “an example of one of the oldest of human impulses: using brute force and disinformation to satisfy a craving for absolute power and control,” Biden declared before a crowd of hundreds of people in the courtyard of the Royal Castle and several thousand more outside its stone walls, watching on a large screen.

“We need to be clear: this battle will not be won in days or months either,” the President said. “We need to steel ourselves for the long fight ahead.”

Administration officials have been careful not to hint at Putin’s removal from office, knowing that it would be taken by the Kremlin as a dangerous escalation. Shortly after Biden’s speech concluded, the White House insisted that the President was not calling for regime change with his comment about Putin remaining in power, which appeared to be ad-libbed.

“The President’s point was that Putin cannot be allowed to exercise power over his neighbours or the region,” a White House official said in a statement. “He was not discussing Putin’s power in Russia, or regime change.”

But some experts said Biden may come to regret the comment. “The White House walk back of @POTUS regime change call is unlikely to wash,” Richard Haass, the president of the Council on Foreign Relations, said in a tweet. “Putin will see it as confirmation of what he’s believed all along. Bad lapse in discipline that runs risk of extending the scope and duration of the war.”

Kremlin spokesman Dmitri S. Peskov told Reuters: “That’s not for Biden to decide. The President of Russia is elected by Russians.”

Biden unleashed an angry tirade against Putin for having the “the gall” to say his invasion is intended to “de-Nazify” Ukraine. Biden called that claim “a lie,” noting that President Volodymyr Zelensky is Jewish and his father’s family was killed in the Holocaust.

“It’s just cynical. He knows that. And it’s also obscene,” Biden said.

Hours earlier, Biden reacted emotionally following a brief interaction with refugees from Ukraine who had come to Warsaw. After holding a small Ukrainian girl in his arms for a selfie, the President responded to a question from a reporter by calling the Russian leader “a butcher” for the crushing shelling of Mariupol, the eastern city in Ukraine, which has been largely demolished by Russian forces.

Administration officials had billed Biden’s address as a “major speech” at the conclusion of three days of presidential-level diplomacy in Europe, and the President seemed eager to speak more bluntly than is common in diplomatic venues.

In his telling, Putin was “bent on violence in the start,” later adding, “It’s Vladimir Putin, who is to blame. Period.” More broadly, he accused Putin of reviving the Cold War that pitted America against the Soviet Union for decades in a perilous face-off between nuclear-armed powers.

(New York Times News Service)