Turkish President Recep Tayyip Erdogan has asked Russia to prove its claim that Ankara shot down a Russian fighter jet in order to protect its oil trade with ISIS.

“If you allege something you should prove it,” he said.

Recep Tayyip Erdogan was responding to a statement by Russian President Vladimir Putin saying that Turkey downed the jet as it was flying over Syria.

Turkey says the warplane entered its airspace and was warned to leave.

One Russian pilot was killed and the other rescued after Russia’s Su-24 bomber was shot down by a Turkish F-16 fighter on the Syrian border on November 24.

A Russian marine was killed during the rescue operation in north-western Syria.

Russia has insisted the fighter jet did not cross the border and that it gave advance notice of the flight path to the US, Turkey’s ally.

The US has supported Turkey’s version of events.

Photo Reuters

“You should put your documents on the table if you have any. Let’s see the documents,” Recep Tayyip Erdogan said.

“We are acting with patience. It is not positive for the two countries which have reached a position which could be regarded as a strategic partnership to make emotional statements.”

Recep Tayyip Erdogan also vowed to step down if the allegation that Turkey was buying oil from ISIS proved true, suggesting that President Vladimir Putin should do the same if he was wrong.

Russia is a major ally of Syrian President Bashar al-Assad and its air strikes have targeted rebel groups, including ISIS.

Turkey strongly opposes Bashar al-Assad and has been accused of turning a blind eye to jihadist fighters crossing from its territory into Syria.

Until a few months ago, Turkey was reluctant to play an active role in the coalition against ISIS. However, in August it allowed the US-led coalition to begin using its airbase at Incirlik.

Russia has imposed sanctions on Turkey over the downing of the warplane, including restrictions on imports of Turkish food and an end to visa-free travel.

ISIS earns much of its money from illegal oil fields it controls in north-eastern Syria and western Iraq.

Some of the oil is sold to the Assad regime and some is smuggled through middlemen to Turkey. However, the Turkish government has consistently denied being involved in the trade.

“We have every reason to think that the decision to shoot down our plane was dictated by the desire to protect the oil supply lines to Turkish territory,” Vladimir Putin said at a news conference in Paris on November 30.

Vladimir Putin also accused Turkey of harboring “terrorist organizations” operating “in various regions of Russia, including the North Caucasus”.