Russian forces corner Ukrainian troops in key city as U.S. plans more military aid
Ukrainian troops are fighting to maintain control of the eastern city of Severodonetsk as the U.S. and NATO allies prepare to increase military aid. CBS News foreign correspondent Chris Livesay joins CBS News' Elaine Quijano and Errol Barnett with details on that, plus a recent announcement from Russia's U.N. ambassador regarding the passage of grain shipments.