is imminent, but the war games on the country s border are telling a different story. thousands of russian troops conducted military drills using warplanes, naval shipses and ballistic missiles. and while u.s. troops wait on heightened alert here, about 300 antitank missiles and other american-made weapons, like bunker busters arrived in kyiv today. the administration says diplomacy isn t dead but tensions are still mounting. the u.s. and allies have vowed t hit russia with sanctions like never before if moscow invades. we have two reports tonight, one from inside ukraine. but we ll start here in washington with cbs ed o keefe at the white house. reporter: the white house continues to believe russia could invade ukraine at any time and today went further than ever before to make clear, vladimir putin will face economic sanctions if he invades and u.s. troops could be headed to the region sooner rather than later. a russian military show of force today on the country s western border