EU foreign affairs head Catherine Ashton said early Friday the premiers of Serbia and Kosovo made some headway towards normalising ties, during overnight talks in Brussels.
In a statement issued after a six-hour meeting into the early hours, Ashton said the Serbia and Kosovo prime ministers, Ivica Dacic and Hashim Thaci, "agreed a number of open issues, in particular in the field of justice, police and upcoming municipal elections."
But there was no mention of progress to resolve disputes over energy and telcoms since Kosovo broke away from Serbia in 2008, and diplomats said talks on those problems were due to continue at a lower level on Friday.
The two premiers met with Ashton ahead of an EU summit at the end of next week which is due to decide whether to bring them closer within the European fold.
At stake is how far they have implemented an historic April deal to defuse tension in the last Balkans' trouble-spot.
Ashton said she believed that "good work has been done and concrete progress has been achieved."
"I will now inform the (EU) member states about the progress in the implementation of the April Agreement, confirming that concrete steps towards a visible and sustainable improvement of relations between the two sides were taken," she added.
But diplomatic sources indicated that work remained to be done before the EU's 27 leaders -- to be joined on July 1 by new member Croatia -- decide at a June 27 and 28 summit whether sufficient progress has been achieved by Belgrade and Pristina in honouring the accord.
If so, Belgrade will be offered a start date to open negotiations for EU membership and Pristina a partnership accord, pending recognition by all of the bloc's members.
The two capitals this week exchanged liaison officers and Belgrade began to close down police stations in northern Kosovo that are run by the Serbian home affairs ministry, but has yet to agree how many of the hundreds of police will join the Kosovo force.
The moves are part of the April deal allowing some autonomy for the 40,000 ethnic Serbs living in northern Kosovo who, like Belgrade, refuse to recognise Pristina.
The accord, which has not been formally published, offers the Serbs the post of police chief in the area as well as the majority voice in local courts but states that both the police and judiciary remain under Kosovo's control.
However, two months after the EU-brokered April 19 agreement, Kosovo has no international dialling code as an independent country because of Serbia's opposition.
Kosovo declared independence in 2008, but when it comes to phone lines, it is still part of Serbia, which has refused to recognise the breakaway territory's sovereignty.
Mobile phone operators who moved into Kosovo after Serb forces were driven out, issue Kosovo numbers with the national codes for Monaco (+377) or Slovenia (+386).
On energy, Kosovo likewise wants to win independence from Serbia in importing and exporting electricity. Currently all power goes through Belgrade in accordance with a scheme dating back to the former Yugoslavia.
Serbia wants its own electricity company to continue supplying Serb-dominated areas in Kosovo; Pristina insists on control over its entire territory.