Anyway, the source for this is the WSJ and it is paywalled (also available on other outlets):
If you believe the walk back, you're a moron. I don't disagree with the comment, but it probably wasn't the most helpful to not further antagonize Putin.WARSAW—President Biden appeared to call for Vladimir Putin’s ouster in a speech Saturday, saying the Russian president’s invasion of Ukraine had ignited a “new battle for freedom” between democracies and autocracies.
“For god’s sake, this man cannot remain in power,” Mr. Biden said at the Royal Castle before nearly a thousand attendees, including Polish President Andrzej Duda and members of the parliament. Hundreds of Poles also gathered nearby to watch a live stream of the speech.
A White House official later walked back Mr. Biden’s comment. “The president’s point was that Putin cannot be allowed to exercise power over his neighbors or the region,” the official said. “He was not discussing Putin’s power in Russia, or regime change.”