Any peace deal that would see Ukraine cede territory to Russia in hopes of ending the war would be deeply unpopular with the Ukrainian people. It would also be illegal under the country’s constitution.

Moscow's forces are making gains near Pokrovsk in Ukraine's Donetsk region, according to the Institute for the Study of War.

The threats, pressure and ultimatums have come and gone, but Russian President Vladimir Putin has maintained Moscow’s uncompromising demands in Ukraine, raising fears he could use a planned summit with U.