EU foreign ministers, meeting in Brussels, said that both Serbia and its neighbour Bosnia had to do more to bring high-ranking suspects such as Radovan Karadzic and Ratko Mladic to justice, but fell short of setting a deadline.

"There is no ultimatum on the agenda for the moment," noted German Foreign Minister Frank-Walter Steinmeier as he arrived for the meeting in Brussels.

EU Enlargement Commissioner Olli Rehn submitted a report to the ministers saying Belgrade's progress has fallen short of expectations. Rehn told the foreign ministers that "Serbia has a few weeks more" to fully cooperate but did not set any firm deadline.

British Foreign Secretary Jack Straw said that Serbia's Stabilization and Association Agreement (SAA) talks, seen as a first step to joining the Union, were at particular risk.

"If Serbia continues to fail to cooperate they risk an end, a total suspension, of the talks," Shaw told reporters.

War criminals still at large

A decade after the war in Bosnia that claimed 200,000 lives and left more than two million homeless, the conflict's most wanted men, former Bosnian Serb political leader Karadzic and military chief Mladic, are still on the run. Both men have been indicted by the International Criminal Tribunal for the former Yugoslavia (ICTY) in The Hague for genocide and other crimes, including ordering the Srebrenica massacre of 8,000 Muslims at the end of the 1992-1995 war.

Europe failed utterly to prevent the conflict, but the prospect of joining the rich 25-member club has become a powerful incentive for the economically ravaged Balkans states.

Both men have been able to evade capture for more than a decade. Last week, Serbian media reports suggested that Mladic, who is believed to be hiding in Serbia, had either been located, was negotiating his surrender or was already under arrest. Belgrade denied this.

A carrot on a stick

In conclusions from their talks, the EU ministers "urged both Serbia and Montenegro and Bosnia and Herzegovina to take decisive action to ensure that all remaining fugitive indictees, notably Radovan Karadzic and Ratko Mladic, are finally brought to justice without delay."

They noted that "full cooperation with the ICTY must be achieved to ensure that the SAA negotiations are not disrupted."

Serbia and the EU began negotiating the association agreement in November. The next round of talks is scheduled for April 5.

Last year, the EU delayed the start of full membership talks with Croatia, another of the former Yugoslav republics, for not doing enough to help the court find a major suspect, General Ante Gotovina. Gotovina was arrested in early December after four years on the run.