The European Commission has written to Serbia, warning that time is running out for it to arrest war crimes suspect Ratko Mladic if it wants to conclude an agreement this year on closer ties.
European Enlargement Commissioner Olli Rehn stressed to Serbian Prime Minister Vojislav Kostunica the need for action to achieve full cooperation with the UN war crimes tribunal.
The EU suspended negotiations with Belgrade on a first-level association agreement in May after Serbia failed to make good on a promise to hand over the former Bosnian Serb military chief to the Hague tribunal for trial on genocide charges.
Serbia put forward an action plan in July outlining proposed steps to achieve full compliance with the UN tribunal, but EU officials say there has been little action so far and no word of improvement from chief war crimes prosecutor Carla del Ponte.
"The letter emphasises the need for action now because there is a risk of running out of time to finalise negotiations by the end of the year if it doesn't happen soon," a UN official said.
EU officials said politicians in Belgrade still seemed to believe they could restart talks with Brussels without arresting Mladic if they showed more goodwill, citing the example of Croatia, which had been allowed to open accession talks before the capture of war crimes suspect Ante Gotovina.
However, the officials said Croatia had given Ms del Ponte proof that Gotovina was not in the country and evidence of where he was and how to trace him. Serbia had produced no such evidence on Mladic, they said.