Turkish President Recep Tayyip Erdogan on Thursday said Turkey does not buy any oil from Islamic State , insisting that his country's fight against the jihadist group is "undisputed."<br />"Shame on you.<br />Those who claim we buy oil from Daesh (IS) are obliged to prove it.<br />If not, you are a slanderer," Erdogan said, lashing out at Russian charges after the downing of a warplane on the Syrian border.<br />Erdogan also said that Russia was Turkey's biggest energy supplier, followed by Iran.<br />Turkish F-16 jets shot down a Russian warplane on the Syrian border on Tuesday, prompting a tough response from Moscow, a major trade partner of Ankara.<br />Russian President Vladimir Putin has denounced the act as a "stab in the back" by "accomplices of terrorists."
