Russia's upper house of parliament has asked President Putin to recall the Russian ambassador to the USA, Reuters reports.
The call came after the house overwhelmingly approved an proposal by Putin to deploy Russian armed forced in Ukraine's Crimea region.
The house backed a proposal to back a proposal to use:
The armed forces of the Russian Federation on the territory of Ukraine until the normalisation of the socio-political situation in that country.
Pro-Russia activists recaptured administrative headquarters in the Ukrainian city of Donetsk and flew the Russian flag from its roof.
ITV News' Europe Correspondent describes the tense atmosphere surrounds a central government building in Donetsk .
New footage obtained by ITV News shows Russian troops firing warning shots as Ukrainian soldiers approached during a tense stand-off today.