They were among the final few words of a carefully crafted speech. But they strayed far from the delicate balance that U.S. President Joe Biden had tried to strike during three days of wartime diplomacy in Europe.

"For God’s sake, this man cannot remain in power,” Biden said Saturday, his cadence slowing for emphasis.

On its face, he appeared to be calling for President Vladimir Putin of Russia to be ousted for his brutal invasion of Ukraine. But Biden’s aides quickly insisted that the remark — delivered in front of a castle that served for centuries as a home for Polish monarchs — was not intended as an appeal for regime change.