Pope Francis’s planned trip to Lebanon next month has been postponed because the 85-year-old pontiff experienced difficulty walking recently, sources said on Monday. In recent weeks, the pope suffered a flare-up of pain in the right knee in addition to a long-time case of sciatica, which also causes pain in the legs. The June 12-13 trip had been announced by the Lebanese government. The Vatican never officially announced the trip but the pope referred to plans relating to it in recent interviews. The two sources, who spoke on condition of anonymity because they were not authorised to discuss s…