President Barack Obama is raising the stakes in the West's standoff with Russian President Vladimir Putin. He's imposing sanctions against Moscow and rejecting plans for a referendum on the future of Ukraine's Russian-occupied Crimea. Ukraine Prime Minister Arseniy Yatseniuk says Russian President Vladimir Putin's declaration that he had the right to invade Ukraine amounted to a 'declaration of war': European leaders are putting in place their own measures but are split over how forcefully to follow America's lead. Obama has placed new visa restrictions on Russians and others involved in destabilizing Ukraine's new government. The president also declared the plan from Putin's allies in Crimea for a March 16th referendum on seceding from Ukraine and joining Russia, illegal.