European Commission President Jean-Claude Juncker (L) shakes hands with Serbian President Aleksandar Vucic during a press conference in Belgrade, Serbia on Feb. 26. 2018. The European Union is "keen" to receive Serbia and other Western Balkans countries as members when they meet preconditions, Juncker told Serbian president Aleksandar Vucic on Monday. (Xinhua/Predrag Milosavljevic)