Turkey has claimed Russia is trading oil with the Islamic State, countering Moscow's claims that Turkey's president was personally involved in deals with the terrorist group.

In a televised speech in Ankara Thursday, Turkey's President Recep Tayyip Erdogan said he had "proof" of Russia's involvement with the Islamic State, adding that he would "reveal it to the world," according to newswire AFP.

Erdogan's claims are the latest in the country's war of words which have marred formerly friendly ties between the two nations after Turkey shot down a Russian fighter jet on the Syrian border on November 24, killing one of the two pilots on board.

Evrim Aydin | Anadolu Agency | Getty Images

Russia has gone so far as to accuse Erdogan's family of personal involvement in an illegal oil trade with the Islamic State — the terrorist group which is now the target of both Western and Russian airstrikes in Syria.

"We know who are stuffing pockets in Turkey and letting terrorists prosper from the sale of oil they stole in Syria," Putin said in a televised address to over 1,000 delegates of the Russian Federal Assembly Thursday morning.

"The terrorists are using these receipts to recruit mercenaries, buy weapons and plan inhuman terrorist attacks against Russian citizens and against people in France, Lebanon, Mali and other states," he said.

Erdogan has denied the claims as "slander."

Meeting face-to-face

Turkey's accusation came ahead of the first face-to-face meeting between the countries' high-level officials since the jet was downed last week.

Russia's Foreign Minister Sergey Lavrov and Turkey's Foreign Minister Mevlut Cavusoglu spoke in Serbia Thursday evening during a two-day meeting of the Organization for Security and Co-operation in Europe (OSCE), where issues like Ukraine, migration and terrorism were on the agenda. After the meeting, Lavrov said in Belgrade that he had heard nothing new from Cavusoglu about the downing of a Russian plane by a Turkish military jet, according to Reuters.

Russia's President Vladimir Putin already snubbed an invite to speak with Turkish President Recep Tayyip Erdogan during the kick-off of the United Nations' climate conference in Paris on Monday.

The foreign ministers did speak on the phone last week, but Russia has so far expressed disappointment over Turkey's failure to apologize for the downing of its fighter jet which Turkey claims ignored multiple warnings that it was violating its airspace.