Vladimir Putin's ally, Dmitry Medvedev, issued a harsh rebuke of Donald Trump on Wednesday, saying on Telegram that the U.S. president has "slipped into an alternate reality" after Trump stated on Tuesday that Ukraine can reclaim all territory lost to Russia, marking a sharp shift from his earlier calls for Kyiv to make concessions.

ANALYSIS: Trump said Tuesday that Ukraine was "in a position to fight and WIN all of Ukraine back in its original form" — a notable shift appearing to reflect growing frustration with Russia.

Security experts analyze President Donald Trump's reversal on Ukraine policy as Russia pushes back on his assessment that Ukraine can reclaim all seized territory.

President Trump’s abrupt shift on the war in Ukraine this week came amid fresh frustration at his counterpart Vladimir Putin, and was intended to apply more pressure on Moscow to come to the negotiating table,

Ukrainian President Volodymyr Zelenskiy this week asked U.S. President Donald Trump for Tomahawk missiles to force Russian President Vladimir Putin to make peace, Axios reported on Friday.

President Zelenskyy this week asked US President Donald Trump for Tomahawk missiles to force Russian President Vladimir Putin to make peace.

President Donald Trump has seemingly forgotten one of the biggest insults he has given to Russia as he reiterated his disappointment with Vladimir Putin over the Ukraine war. Two days ago, in a major reversal for the president,

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.