PARIS:- Pop star Lady Gaga has called off the entire European leg of her world tour because of “severe physical pain”, her promoters said Monday. The US singer revealed last week that she has fibromyalgia, a chronic illness which can cause pain all over the body. The 18-city European arm of her “Joanne” tour, which has been postponed until early 2018, was to begin in Barcelona on Thursday, before shows across the continent, including in Milan, Amsterdam, Paris and five in the UK. Her promoters Live Nation said the agony she was experiencing had “impacted her ability to perform”.