A second day of European Union-mediated talks between Kosovo and Serbia has ended with little progress on resolving a long-running customs dispute.

The two sides concluded talks Tuesday in Brussels with an agreement to mutually recognize each others' university diplomas — a key issue for ethnic Albanians living in Serbia, many of whom have diplomas from Kosovo universities. But little progress was made on the border dispute in northern Kosovo, which was high on the agenda of the two-day meeting.

The negotiations are seen as an important step in Serbia's bid to join the European Union. Talks will resume in Brussels next week.

Serbia has refused to accept Kosovo's 2008 declaration of independence, but says it is determined to resolve other differences through negotiations.

Belgrade hopes to be granted EU candidate status when EU leaders meet in Brussels on December 9. But the European Commission has declined to set a date for accession talks until Serbia does more to normalize relations with Kosovo.

The dispute at a border crossing in northern Kosovo sparked violence between the region's Serbs and ethnic Albanians earlier this year, killing one police officer and injuring at least 16 people, including four NATO peacekeepers. Tensions remain high in the region as authorities try to establish border control, while Kosovo's ethnic Serbs fight it. The ethnic Serbs refuse to recognize the government's authority.