US President Brarack Obama has signed an executive order to expand US economic sanctions against Russia over the Kremlin's move to absorb Crimea. Obama's order is directed at Russian President Vladimir Putin's chief of staff and 19 other individuals, as well as a Russian bank. In response, Russia has barred a number of US politicians and White House advisors from entering the country. But at the same time, the Pentagon has confirmed Russia's Minister of Defence has reassured them that Russia has no intention to entering mainland Ukraine.