ISTANBUL, TURKEY - JANUARY 8: President of Turkey Recep Tayyip Erdogan (3rd R) and his Russian counterpart Vladimir Putin (3rd L) along with Serbian President Aleksandar Vucic (2nd R) and Bulgarian Prime Minister Boyko Borisov (2nd L) open the valve during the opening ceremony of TurkStream natural gas pipeline project, at Halic Congress Center in Istanbul, Turkey on January 08, 2020. Photo: Anadolu Agency