During his meeting with Lavrov , Kerry expressed concern about Russian troops amassed on the Ukrainian border , U.S.State Department spokeswoman Marie Harf said . Ukraine is concerned about presence of Russian troops on Ukraine 's border . Russian threats cited as reason for withdrawal , spokeswoman said . Russia seizes naval base in Crimea , captures troops . U.S. , other western allies pull Russia out of G * .
Ukraine is concerned about presence of Russian troops on Ukraine 's border . Russian threats cited as reason for withdrawal , spokeswoman said . Russia seizes naval base in Crimea , captures troops . U.S. , other western allies pull Russia out of G * .