Bulgarian Prime Minister Boyko Borissov attends a news conference with Romanian Prime Minister Viorica Dancila (not in the picture) in Bucharest, Romania, on March 29, 2019. Romania and Bulgaria are cooperating on the Balkans gas hub, with works on the gas interconnector between the two countries expected to be started in June, visiting Bulgarian Prime Minister Boyko Borissov said Friday. (Xinhua/Cristian Cristel)