Serbian President Aleksandar Vucic (R) poses for a photo with European Commission President Jean-Claude Juncker (C) and EU Commissioner for European Neighborhood Policy and Enlargement Negotiations Johannes Hahn 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)