US President Barack Obama has stated that Russia will not be pushed out of Ukraine's Crimea region by military means.
He said that "if the West stays united, Russians will realise they cannot achieve security through brute force."
Obama said that if Russia stays on the current course then Russian isolation "will deepen."
He also stated that the Ukraine crisis "is not another cold war we are entering into."
An unusually frank Nato Secretary General issued an unequivocal warning on the course of events should Russia attack Latvia or Estonia.
The West responds with sanctions and closer political ties with Ukraine as Russia's President seals the annexing of Crimea to much fanfare.
Supporters of the controversial fracking industry believe shale gas could be America's most potent weapon in the stand-off with Russia.