NATO's Secretary-General has condemned the planned referendum in Ukrainian's Crimea region, saying it would break international law and have no "political legitimacy".
The statement was issued after a meeting of ambassadors from 50 nations, including Russia and Ukraine, ahead of Sunday's vote in Crimea.
The so-called referendum in the Ukrainian Autonomous Republic of Crimea planned on 16 March would be a direct violation of the Ukrainian constitution and international law.
If held, it would have no legal effect or political legitimacy.
Holding this referendum would undermine international efforts to find a peaceful and political solution to the crisis in Ukraine.
John Kerry warned of "consequences" after his Russian counterpart made clear Moscow would respect the outcome of Crimea's referendum.
Foreign ministers meeting in Brussels will decide on Monday on sanctions for Russia if there is no de-escalation in Ukraine.
Crimea's new information minister has told ITV News that the planned referendum is no different to the situation in Scotland and Catalonia.