(ANSA) - BELGRADE, NOV 14 - The high-speed rail line between Budapest and Belgrade—a project that has dragged on for over a decade and is being handled by consortia of Chinese companies—was scheduled to open on December 13, but it will not begin passenger service for the time being. The launch has been officially postponed, as announced by the Hungarian Minister for Transport and Investment, Dávid Vitézy—a statement also reported by major Serbian media outlets. The delay is reportedly due to software issues within the safety systems; the Chinese companies are required to ensure these systems are compatible with the European Train Control System (ETCS). During testing conducted in recent weeks, minor software glitches were identified that require resolution. Hungarian Minister Vitézy emphasized that passenger service will not begin until an independent quality control body (TÜV) and the revelant certification authorities confirm that all errors have been corrected and the system is fully functional. The implementation of new train timetables in Serbia, which was also set to take effect on December 13, has likewise been postponed. According to the original plans announced in 2015, —a project touted as the "crown jewel" of the political alliance between Viktor Orbán and Aleksandar Vučić (who was Prime Minister at the time)—the high-speed rail line between Budapest and Belgrade was originally expected to be operational between late 2017 and 2018. The project has faced numerous delays, and its construction is not managed by a single firm, but rather by several consortia led by major Chinese state-owned enterprises (primarily groups affiliated with China Railway and CCCC). (ANSA).