Turkey has challenged Russia to prove its claim that Ankara shot down a Russian plane in order to protect its oil trade with Islamic State (IS), BBC News reports.

"If you allege something you should prove it," Turkish President Recep Tayyip Erdogan said.

He was responding to a statement by Russia's President Vladimir Putin.

"You should put your documents on the table if you have any. Let's see the documents," Mr 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."

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