The Ukrainian president addresses the UN General Assembly after Donald Trump says for the first time that Kyiv could retake its lost borders.

Vladimir Putin ally Dmitry Medvedev issued a harsh rebuke of President Donald Trump on Wednesday, saying on Telegram that Trump has "once again fallen into an alternative reality" after the president said Tuesday that Ukraine can reclaim all territory lost to Russia, marking a sharp shift from his earlier calls for Kyiv to make concessions.

Ukrainian President Volodymyr Zelenskiy urged world powers to help stop Russia's war in his country in a speech to the United Nations on Wednesday, warning of a dangerous arms race that he said the fighting was unleashing.

UNITED NATIONS -- UNITED NATIONS (AP) — President Donald Trump said Tuesday that he believed Ukraine could win back all territory lost to Russia, a dramatic shift from the U.S. leader’s repeated calls for Kyiv to make concessions to end the war.

U.S. ambassador to the United Nations Mike Waltz warns Vladimir Putin that Trump's push for NATO allies to shoot down intruding Russian aircraft is serious.

NATO faces increased Russian testing through gray-zone tactics as Trump warns the Ukraine war could lead to World War III with Moscow.

The "Daily Show" host jokes Trump could switch sides again "if he gets complimented by a Russian lady or sees a photo of that dog that looks like Vladimir Putin"