Recep Tayyip Erdogan
Turkish President Recep Tayyip Erdoğan said he would resign if Russia's claim was provedGetty

Turkish President Recep Tayyip Erdoğan has hit back at his Russian counterpart Vladimir Putin following the accusation that Ankara shot down a Russian warplane to safeguard its oil trade with the Islamic State (Isis). Erdoğan challenged Putin to resign if he is unable to prove the allegations.

Speaking at the UN climate change summit in Paris, the Turkish leader responded to Putin's "slander" by saying: "We are not that dishonest as to buy oil from terrorists. As soon as such a claim is proved, the nobility of our nation requires [me] to do this, I will not remain in this post. But I am asking Mr Putin, would you remain?"

Erdoğan went on to make a counter-accusation and said there is a Russian-Syrian citizen purchasing oil from the IS militants and then selling it to the Syrian regime. "First they [Russia] should give an account of this," he added. "We buy from Russia, Iran, Azerbaijan, Qatar and Nigeria. We won't accept any other slanders."

Earlier, the Russian side, including Putin, alleged they had credible intelligence information to believe Moscow's SU-24 bomber was shot down to secure the oil trade deliveries from Syria to Turkey.

Putin, who is also in Paris for the conference, said: "At the moment we have received addition information confirming that the oil from the deposits controlled by Islamic State militants enters Turkish territory on industrial scale. We have every reason to believe that the decision to down our plane was guided by a desire to ensure security of this oil's delivery routes to ports where they are shipped in tankers." Putin had earlier declined Erdoğan's offer to hold bilateral talks on the sidelines of the summit.

The war of words between the two countries has been constantly escalating ever since the Russian warplane was brought down on 24 November for reportedly violating Turkish airspace. While tension remains high in the region, both sides have refused to back down on the crisis.