US President Joe Biden, who was visiting Europe, said Saturday in Warsaw that Russian President Vladimir Putin should not remain in power after he unleashed the invasion of Ukraine.

"For God's sake, this man cannot remain in power," Biden said during a speech at the royal castle in Warsaw, where he explained that the sanctions on Russia are not aimed at the Russian people

"Let me say this, if you are able to understand, you, the Russian people, are not our enemy," he declared, stressing that "this war is not worthy of you, the Russian people."

But on the other hand, Biden made it clear that his administration does not intend to wage war with the Russian forces that have invaded Ukraine. Nevertheless, he seriously warned, "Don't think to advance an inch into NATO territory."

He then left for the airport, and was due back in Washington overnight last night.