OBAMA TO PUTIN: We Will Punish You For Illegitimate Crimean 'Referendum'

U.S. President Barack Obama spoke with Russian President Vladimir Putin Sunday evening, a tense call on which Obama promised further "costs" for a referendum in Crimea the U.S. and international community will never recognize.

The head of the referendum committee said more than 90 percent of Crimeans had voted in favor of annexation by Russia. In its readout of the call, the White House put the word "referendum" in scare quotes, signifying that it didn't respect the alleged result of the referendum it has long considered to be illegitimate and illegal.

The White House also said Obama told Putin to prepare for additional "costs," likely in the form of sanctions that could be handed down this week.

"President Obama emphasized that the Crimean 'referendum,' which violates the Ukrainian constitution and occurred under duress of Russian military intervention, would never be recognized by the United States and the international community," the White House said in its readout.

"He emphasized that Russia's actions were in violation of Ukraine's sovereignty and territorial integrity and that, in coordination with our European partners, we are prepared to impose additional costs on Russia for its actions. President Obama underscored that there remains a clear path for resolving this crisis diplomatically, in a way that addresses the interests of both Russia and the people of Ukraine."

In its own readout of the call, the Kremlin said Putin defended the Crimean referendum as legitimate and legal. Putin said it was necessary after the new Ukrainian government failed ot "curb rampant violence by ultra-nationalist and radical groups that destabilize the situation and terrorize civilians, including Russian-speaking population."

Tensions have risen in the region over the past few days, as Ukraine accused pro-Russian forces of making their first move outside Crimea and into eastern Ukraine on Saturday - a move the White House said was concerning. Crimea's deputy prime minister said Sunday he thinks Crimea's referendum is "only the first step."