assignments. o donnell: of course she didn t. kris van cleave, thank you so much. we learned in the last 24 hours, there has been an increased russian buildup of troops on the ukraine border. also the u.s. military naming the ten u.s. bases where some 8500 troops are on heightened alert to deploy to eastern europe. cbs s holly williams reports from ukraine s capital of kyiv. reporter: the ball is now in russia s court and today moscow continued its buildup near ukraine s nrthern boarder in belarus for what it says are military trills. russia s demanding security guarantees incl including the rg back of n.a.t.o. forces from eastern europe and a ban on ukraine joining the alliance. the u.s. and its n.a.t.o. allies say they cannot agree to either. the american ambassador to russia hand delivered a written response yesterday. today the kremlin said the u.s. had not addressed its main concerns and likened the current