Russian President Vladimir Putin and Turkish President Recep Tayyip Erdogan agreed that Ankara would switch part of its payment for Russian natural gas to rubles, in what appeared to be the most concrete result of their four-hour long meeting in the Black Sea resort town of Sochi today.

“We are gradually switching to national currencies, and at the first stage part of supplies will be paid in Russian rubles. This is really a new stage, new opportunities, including for the development of our monetary and financial relations,” Russia’s Deputy Prime Minister Alexander Novak told reporters after the meeting.

In a joint statement the pair agreed to boost cooperation in transport, agriculture, finance and construction. The statement said that the two leaders "reaffirmed their determination to act in coordination and solidarity in the fight against all terrorist organizations" in Syria.

But there was no word of a green light for Turkey’s planned military intervention against US-backed Kurdish forces in northeast Syria. Putin is believed to have made his opposition to another large-scale intervention clear in a July 19 meeting with Erdogan in Tehran. Russian official say any such move would further destabilize Syria. Iran, the Assad regime’s other main backer, is also against an expansion of Turkey’s already substantial occupation of Syria.