By Daily Mail Reporter PUBLISHED: 13:32 EST, 6 March 2014 | UPDATED: 21:42 EST, 6 March 2014 Barack Obama ordered the West's first sanctions in response to Russia's military takeover of Crimea on Thursday, declaring his determination not to let the Kremlin carve up Ukraine. The President asserted that a hastily scheduled referendum on Crimea seceding and becoming part of Russia would violate international law. European leaders announced their own measures but split over how forcefully to follow America's lead. Obama threatened further steps if Russia persists. Laying down the law: President Obama said that America is working in conjunction with international partners but also signed an executive order to levy sanctions on Russia and revoked visas for certain Russian nationals
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Proposed referendum 'violates international law' U.S. President says
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U.S. pulls visa approval for anyone helping destabilize the Ukraine and left the path open for future financial sanctions
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The @placeholder is also calling on Russia to recognize the legitimacy of Ukrainian plans for elections in May, not the Crimean referendum a week from Sunday.
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On guard: The @placeholder parliament called a referendum on March 16 to secede and join Russia but international leaders, including President Obama, says taht is illegal
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Russian troops have seized control of much of Crimea, where ethnic @placeholder are the majority.
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Any such referendum, he said, must include representatives from the legitimate @placeholder government- which was not included in the original plan.
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They would also prohibit @placeholder persons from doing business with those who have been sanctioned.