U.S. official : Tens of thousands of Russian troops along border have been moving back . Comment: It could be intended to goad Moscow into a response at a time when the separatist movement is under pressure to find a way forward and has shown signs of division within its ranks . Donetsk governor says he is in talks with separatist leaders , aims to calm situation . Self-declared separatist mayor of Slovyansk says militants hold 4 missing OSCE monitors .
U.S. official : Tens of thousands of Russian troops along border have been moving back . Comment: Donetsk governor says he is in talks with separatist leaders , aims to calm situation . Self-declared separatist mayor of Slovyansk says militants hold 4 missing OSCE monitors .