U.S. President Barack Obama (R) sits alongside Prime Minister of Australia Tony Abbott (L) and British Prime Minister David Cameron during a plenary session at the G20 leaders summit in Brisbane November 15, 2014. Western leaders attending a G20 summit blasted Russian President Vladimir Putin on Saturday for the crisis in Ukraine, threatening further sanctions if Russia did not withdraw troops and weapons from its neighbouring nation. REUTERS/Rob Griffith/Pool (AUSTRALIA - Tags: POLITICS BUSINESS)