In October 2013, arrangements were made for a visit by Serbian officials to northern Kosovo.  It was agreed that Kosovo`s electoral bodies would also include representatives of Kosovo-Serb and that the international code 383 would be assigned to Kosovo.  The new code was due to come into force at the end of 2015, but was again postponed until March 2016 by Serbia.  The geographic telephone code was implemented in December 2016.  To date, ten roundtables have been held at the European External Action Service office in Brussels. Ashton, the EU`s High Representative, chaired the talks for two years, followed by Federica Mogherini. The normalisation of relations with neighbouring countries is an important condition for states wishing to join the EU; The Brussels agreement led Serbia to sign a Stabilization and Association Agreement (ASA) just before the EU accession negotiations and Kosovo. The ASA was signed by HR Mogherini and PM Mustafa in October 2015. One of the most difficult problems remains to eliminate parallel Serbian structures in the northern part of Kosovo until full sovereignty. 1. In Kosovo, there will be an association/community of majority Serb communities. Membership is open to any other municipality, subject to the agreement of the members.
Following the conclusion of the agreement, the European Commission officially announced that work on the ASA with Kosovo and accession negotiations with Serbia had begun. The agreement was supported by the European Union, NATO, the OSCE and the United Nations.  The Kosovo Assembly ratified the agreement, incorporated it into a law and treated it as an “international agreement”.  The Serbian National Assembly did not treat the agreement as international and did not ratify it in a binding law, which is a necessary procedure for international agreements in Serbia.  However, it only accepted the government report on “the process of political and technical dialogue with the temporary institutions of Pristina, under the aegis of the EU, including the process of implementing the agreements reached”.  The Constitutional Court of Belgrade did not respond to the question of the constitutionality of the agreement and stated in December 2014 that the issue raised was political and not legal. The Brussels agreement (Serbian: Briselski sporazum, in Albanian: Marréveshja e Brukselit), formally the first agreement to normalize relations, was concluded between the governments of Serbia and Kosovo on the normalization of their relations.  It was negotiated and concluded in Brussels under the auspices of the European Union, although it was not signed by any of the parties. The negotiations were led by Serbian Prime Minister Ivica Dasai and Kosovo Prime Minister Hashim Thai and were negotiated by EU High Representative Catherine Ashton.
The agreement was reached on April 19, 2013.  The Serbian government does not recognize Kosovo as a sovereign state, but has begun to normalize relations with the Kosovo government in accordance with the Brussels agreement. The notion of normalization of relations remains vague and therefore largely problematic.  However, Serbia has agreed that progress in implementing the Brussels agreement will be a precondition for EU accession negotiations as part of the opening of Chapter 35 negotiations in December 2015. [Citation required] Under the Brussels agreement, meetings are held regularly to ensure the implementation of provisions in various areas. An agreement on justice was reached in February 2015, followed by agreements on energy and telecommunications operators. On 25 August 2015, an agreement was reached for the creation of the Serbian Community Association, which is at the heart of the Brussels agreement.