US Secretary of Sate John Kerry accused Russia of intimidation and aggression against Ukraine.
He said the "Russian government is trying to make the world believe, against all evidence, it is representing Ukrainian people."
"Not a single piece of evidence supports any of Russia's claims. None," the top American diplomat said."There's a better way for Russia to pursue its interest in Ukraine," Mr Kerry added.
Russian president Vladimir Putin said he would only use force in Ukraine as a "last resort" as he defended Russia's actions in Crimea.
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