Serbian Prime Minister Aleksandar Vucic has cut short a visit to Brussels amid a dispute with European Union-member Croatia.
The dispute is over what Belgrade claims are attempts by Croatia to block Serbia's progress toward EU membership.
Vucic had been due to attend a meeting of the EU Intergovernmental Conference on December 13 for the expected approval of opening three new accession chapters in Serbia's EU member application.
Zagreb objects to opening the chapter on culture and education because of a dispute about the translation of school textbooks.
Croatia's Minister for Foreign and European Affairs Davor Ivo Stier said "full protection of national minorities" is one of the things "Serbia must implement along its EU path."
Serbian Foreign Minister Ivica Dacic on December 12 said that "if Croatia is the one to decide about whether Serbia will enter the EU, then my interest just dropped somehow."
Based on reporting by Reuters, Tanjug, and HINA