(Reuters) – Ukrainian President Zelenskiy said his country had reached a “strategic turning point” in the war. Satellite images showed Russian military units closer to the capital Kyiv and firing artillery toward residential areas. FIGHTING * The situation in Ukraine’s southeastern city of Mariupol was critical, officials said, as Russian forces tightened their noose around the Black Sea port and the death toll from shelling and a 12-day blockade reached almost 1,600. * Britain said Russian air and missile forces had conducted strikes in the past 24 hours against the western Ukrainian cities o…