A tank drives in the center of the eastern city of  Donetsk. Kiev's pro-Western leaders and mediators hoped to reach a "binding" truce with pro-Russian separatists on January 31, 2015 despite Ukraine suffering one of its bloodiest days yet in the nine-month conflict with 15 troops killed.  AFP PHOTO / DOMINIQUE FAGET        (Photo credit should read DOMINIQUE FAGET/AFP/Getty Images)