EU leaders set to warn, not sanction Russia; U.S. crude stocks rise more than expected. U.S. jobs data, services data point to lower oil demand. Brent crude reversed gains made earlier on Thursday after Crimea's parliament voted unanimously to join Russia, even as the West and Russia engaged in high-stakes diplomacy to cool the crisis in Ukraine. The announcement sets a referendum on the future of Crimea in 10 days, raising the stakes in the most serious East-West confrontation since the end of the Cold War. The North Sea benchmark has fallen $4 since reaching two-month highs on Monday, when worries of an armed conflict between Ukraine and Russia peaked.