US President Donald Trump handed the Kremlin a clear warning this week,announcingplans for weapons supplies to Kyiv via Europe and saying the United States will impose very severe tariffs on Russia if it doesnt reach a deal on the war in Ukraine within 50 days.

Trump did not specify whether a cease-fire would suffice, or only a comprehensive peace deal. Either way, many analysts say its unlikely to happen. Heres why.

Territorial Aims

Russian President Vladimir Putins goals clearly go far beyond the conquest of part of Ukraine: He has made plain that he wants to subjugate the country and weaken NATO and the West, restoring a measure of Moscows Soviet-era sway over swaths of Europe.

But a more immediate aim is all about territory. Russia occupies about 20 percent of Ukraine. In addition to the Crimean Peninsula, which Russia has controlled since 2014, Putin formally and falsely claims that the Ukrainian mainland regions of Donetsk, Luhansk, Zaporizhzhya, and Kherson are now Russian -- including the substantial portions that Russia does not occupy.

Russia has said a full Ukrainian withdrawal from those four regions is a prerequisite of any peace deal -- a demand that Kyiv says is unacceptable. And while analysts say Putin could weather any backlash at home if he agreed to a pact that would limit Russias presence to the land it now holds, he has given zero indication that he might do that.