The latest on the Russia–Ukraine crisis, March 20. Click here for updates from March 19. Ukraine Refuses Russia’s Demands to Lay Down Arms in Mariupol Ukraine said there is no question of surrendering the city of Mariupol after Russia called on Ukrainian forces on Sunday to lay down arms in the besieged port city. “There can be no question of any surrender, laying down of arms,” the Ukrainska Pravda news portal cited Ukraine’s Deputy Prime Minister Iryna Vereshchuk as saying. “We have already informed the Russian side about this.” Russia said a “terrible humanitarian catastrophe” was unfolding in Mariupol. “Lay down your arms,” Colonel-General Mikhail Mizintsev, the director of the Russian National Center for Defense Management, said in a briefing distributed by the defense ministry. “A terrible humanitarian catastrophe has developed,” Mizintsev said. “All who lay down their arms are guaranteed safe passage out of Mariupol.” Mariupol has suffered some …