Turkish President Recep Tayyip Erdogan has dismissed Russian claims he is benefiting from the oil trade with the Islamic State group as “slander”.
Russia has said Turkey is the biggest buyer of oil smuggled from IS-held territory, accusing Mr Erdogan and his family of direct involvement.
But the Turkish president said he would resign if such allegations were proved.
Russia and Turkey are locked in an angry spat over the downing of a Russian fighter jet by Ankara.
Responding to the allegations, Mr Erdogan said “no one has a right to engage in slander against Turkey by saying that Turkey is buying oil from Daesh [IS]”.