The United States has denied a sanctions waiver to Serbian refinery Naftna Industrija Srbije (NIS), majority owned by Russian state energy firms and sanctioned by the United States, forcing Serbia’s only refinery to shut down, Serbian President Aleksandar Vu?i? said on Tuesday. “We expected to get a license from the US government for continued oil supplies to our refinery in Pancevo...but we have not received a positive decision from the US,” Vu?i? said at a briefing today, as quoted by the Tanjug news agency. …