In a telephone conversation Prime Minister Boyko Borissov and Serbian President Aleksandar Vucic have discussed diversification of gas supplies through the Balkan gas hub project. Borissov has indicated that he would unite supplies from several directions. The implementation of the interconnector projects between Bulgaria and Serbia and the expansion of the pipeline from the Turkish-Bulgarian to the Bulgarian-Serbian border is also crucial. This will ensure energy security for our countries, the Prime Minister said. Vucic thanked for the letter supporting Serbia's European perspective that Bulgaria, Romania and Greece have sent to the German Chancellor and President of France.