U.N. to vote Tuesday on Syria sanctions despite Russia veto pledge

By Michelle NicholsUNITED NATIONS (Reuters) - The U.N. Security Council is set to vote on Tuesday on a bid by Western powers to ban the supply of helicopters to the Syrian government and to blacklist Syrian military commanders over accusations of toxic gas attacks, despite a pledge by Russia to veto the move.The Security Council showdown - pitting Syrian ally Russia against the United States, France, Britain and others - comes amid U.N.-led peace talks between the warring Syrian parties in Genev