The latest round of EU-sponsored talks aimed at normalising relations between Serbia and breakaway Kosovo began Tuesday, amid calls for the two sides to settle their differences.
EU foreign affairs head Catherine Ashton is hosting the Serbian and Kosovar prime ministers, Ivica Dacic and Hashim Thaci, for an eighth round of talks aimed at easing tensions and paving the way for closer ties with the EU.
Ashton said Monday she believed an agreement "is within reach -- though it will not be easy," adding: "We must not let this opportunity pass."
Washington also pressed Serbia and Kosovo to reach an accord but Serbian President Tomislav Nikolic played down any hope of a breakthrough.
"Intractable statements from Pristina put us before a fait accompli and are not encouraging," Nikolic said Monday.
Majority ethnic Albanian Kosovo unilaterally declared independence from Serbia in 2008, winning recognition since then from around 100 countries, including the United States and most EU member states.
Belgrade and Serbs living in Kosovo reject its independence, with the fate of some 40,000 Serbs in the north proving key to a deal.
Both sides have agreed to establish an association of Serb municipalities but Pristina refuses to grant it the executive and judicial power demanded by Belgrade.
"We must ensure the rights (for the association) are guaranteed not only by an agreement between Belgrade and Pristina, but also by the international community, primarily through the EU in its role as a mediator," Nikolic said.
Before leaving Pristina, Thaci said he was expecting an agreement on Tuesday.
Progress at the talks is seen as essential to keeping the momentum going.
Serbia hopes to be given a date to start EU accession talks at a summit in June, while European Commission president Jose Manuel Barroso has said Kosovo could get an agreement on an association accord at the same time.