vaccines. on friday, mitchell wrote on her web site, "irresponsible people are spreadig lies that are costing people their lives." spotify has not responded to cbs news request for comment. the united states is sending urgent alarms about the dangers of of a possible russian attack on ukraine. moscow has moved tens of thousands of troops to the border region. cbs' holly williams is in the capital kyiv. >> reporter: president biden believes there is a distinct possibility that russia could invade ukraine next month. russia has massed roughly 100,000 troops along ukraine's border, and has been moving hardware, including fighter jets and missile systems into neighboring belarus for what it says are military exercises. now, experts say russian military drills have previously been a prelude to an incursion. but here in ukraine's capital kyiv on friday, we were at a press conference given by the country's president, volodymyr zelensky, when he told