Russian President Vladimir Putin and Saudi Arabia's Crown Prince Mohammed bin Salman exchanged a high-five and laughed heartily together on Friday as they took seats next to each other at a plenary session of the Group of 20 summit.
Russia has refrained from criticising Saudi Arabia over the killing of Saudi journalist Jamal Khashoggi at the Saudi consulate in Istanbul.
Putin said in October he lacked information about the matter and said Russia would not tear up its relations with Saudi Arabia because of it.
Putin and Prince Mohammed are due to hold bilateral talks on Saturday, according to Kremlin documents seen by Reuters.
The Organization of the Petroleum Exporting Countries as well as Russia and other leading oil producers will meet in Vienna on Dec 6-7 to discuss further steps on the oil market as prices have been declining due to oversupply.
Riyadh has suggested OPEC and its allies reduce output by 1 million barrels per day from January 2019 to stem the price falls.
* This story was edited by Ahram Online.