U.S. President Joe Biden urges Russia's President Vladimir Putin to put an end to the war they are waging against Ukraine, warning that the United States and its allies will continue to back up Ukraine as it pushes new sanctions against Kremlin.

Biden made the statement from Warsaw, Poland, a day after making a surprise visit to Ukraine, which White House officials described as "unprecedented in modern times."

The U.S. president noted that Putin is faced with a "more united and more unified" NATO, which he noted as something the Russian president did not think was possible a year ago, as reported by Fox News.

Biden said that Putin does not have any doubt about the strength "of our coalition," but still has skepticism on the alliance's conviction, with the president saying, "he doubts our staying power."

The president clarified that the United States and Europe are not seeking "to control or destroy Russia," adding that the war was "never a necessity."

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Russia and U.S. Nuclear Deal

Putin announced that he will be suspending Russia's involvement in a nuclear deal as Biden vowed that the U.S. and its allies will not be backing down.

The Russian president said that he was taking action because of the U.S. and NATO but did not specify anything more, as cited by USA Today.

New START is the nuclear arms reduction deal between the U.S. and Russia, which was signed in 2010 and extended for five years in 2021. The deal limits Russia and the United States to 1,550 long-range nuclear warheads.

U.S. Secretary of State Antony Blinken commented on Putin's decision and described it as "deeply unfortunate and irresponsible." Blinken said that the U.S. will be watching "carefully" to see Russia's actual decision.

Putin argued that NATO allies had helped Ukraine launch drone attacks on Russian air bases, which were home to nuclear-capable strategic bombers.

Pres. Joe Biden Visits Ukraine

Biden has scheduled to fly out from the U.S. to Warsaw on Monday for a two-day trip. The president then spent 10 hours on a train to get to Kyiv, according to BBC News.

Conservative Republicans have criticized the president's travel to Kyiv, an active foreign war zone, without any military presence. The Republicans argued that it would have been better off being seen at the border with Mexico or Ohio, which was affected by toxic waste spilled from a train.

Rep. Marjorie Taylor Greene said on Twitter that the U.S. president "chose Ukraine over America" while making the American people pay for Ukraine's government and war.

East Palestine's mayor Trent Conaway said that the president's visit to Ukraine shows that "he doesn't care about us," describing it as the "biggest slap in the face."

Biden was seen beside Ukraine's President Volodymyr Zelenskyy with the sound of air raid sirens.

White House communications director Kate Bedingfield noted that it was "risky and should leave no doubt in anyone's mind" that Biden takes commitment seriously.

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This article is owned by Latin Post.

Written by: Mary Webber

WATCH: Biden and Zelenskiy walk in Kyiv as air raid sirens blare - from Guardian News