Russia threatened economic retaliation against Turkey on Thursday and said it was still awaiting a reasonable explanation for the shooting down of its warplane, but Turkey dismissed the threats as "emotional" and "unfitting."
In an escalating war of words, President Tayyip Erdogan responded to Russian accusations that Turkey has been buying oil and gas from Islamic State in Syria by accusing Syrian President Bashar al-Assad and his backers, which include Moscow, of being the real source of the group's financial and military power.
The shooting down of the jet by the Turkish air force on Tuesday was one of the most serious clashes between a NATO member and Russia, and further complicated international efforts to battle Islamic State militants.
World leaders have urged both sides to avoid escalation. In an apparent attempt to cool the dispute - and appeal to Western countries - Turkish Prime Minister Ahmet Davutoglu said in a letter to Britain's Times newspaper that Ankara would work with its allies and Russia to "calm tensions".