U.S. warns of Putin againts using nuclear weapon as Russians flee to avoid reservist call up.

NBC's Jay Gray joins Shep Smith to report on the latest news from Ukraine, including the 'sham' referenda Russia is holding in annexed parts of the country and the lengths Russians are going to in order to avoid President Vladimir Putin's reservist call up. For access to live and exclusive video from CNBC subscribe to CNBC PRO: https://cnb.cx/2NGeIvi