David Cameron has warned Vladimir Putin there will be "consequences" if Russian troops are not withdrawn from Ukraine.
Arriving at a summit in Brussels where EU leaders are due to consider beefing up sanctions against Moscow, the Prime Minister said the incursion was "completely unacceptable".
Mr Cameron, who held talks with Ukraine president Petro Poroshenko in Brussels earlier, said: "We have to address the completely unacceptable situation of having Russian troops on Ukraine soil.
"Consequences must follow if that situation continues and we will be discussing that as well today."
Were the Russians -as Barack Obama claims - weighed down by sanctions, or where the Ukrainians looking to cut their losses?
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