Tensions rise as EU agrees Kosovo mission

European Union leaders have agreed to send a 1,800-strong policing and security mission to Kosovo ahead of the province's imminent decision to declare independence from Serbia.

At a summit in Brussels yesterday, EU leaders offered Serbia the carrot of eventual membership of their club, which currently has 27 member states, in an attempt to head off a new Balkans crisis over Kosovo. But Belgrade swiftly rejected the idea of such a trade off. Vuk Jeremic, the Serbian Foreign Minister, dismissed it as "an indecent proposal".

The EU mission, to be dispatched soon after Christmas, will also include administrators and justice officials and would replace the current United Nations administrative mission in Kosovo, which has an ethnic Albanian majority. But the move will anger Russia because a UN effort to resolve the Kosovo crisis has not formally ended and is due to be discussed by the Security Council next week.

EU leaders backed the mission in principle without endorsing independence, expected to be declared next year by the new government. Recognition of a breakaway state will be left to individual EU countries.

The EU leaders did agree that the UN process had run into the sand and, therefore, that they would have to intervene. "Russia is not going to hold Serbia's feet to the fire," one EU diplomat said.

Jose Socrates, the Prime Minister of Portugal, who chaired the summit, said: "We took a political decision to send an ESDP [European Security and Defence Policy] mission to Kosovo. This is the clearest signal the EU could possibly give that Europe intends to lead on Kosovo." Nicolas Sarkozy, the French President, told a news conference that the EU had "a difficulty with Kosovo, which everybody can see will be independent". Cyprus, Greece, Slovakia and Romania object to recognising Kosovo's sovereignty without a UN Security Council resolution.

The EU leaders agreed a statement urging Belgrade to give high priority to meeting conditions for membership so "progress on the road towards the EU ... can be accelerated". They said Serbia should be "fully integrated into the family of European nations", which was "important for the stability of the region".

The crucial hurdle will be the handing over of fugitives wanted for war crimes, including the former military chief Ratko Mladic and the Bosnian-Serb leader Radovan Karadic. They were indicted on genocide charges by the UN war crimes tribunal for former Yugoslavia in The Hague and are said to be hiding in Serbia. It has offered a 1m (715,000) reward for Mladic's arrest but not for Karadic, because he not a Serb citizen.

The offer of EU membership to Croatia did pave the way for some of their generals to be captured. But Britain did not want a formal link between the looming crisis over Kosovo and a fast-track to the EU for Serbia. The UK was among the EU members who wanted to stress that Belgrade should first hand over those wanted for war crimes.

Gordon Brown insisted that the legal basis for the mission had been established a claim which is disputed by Serbia and Russia, which argue that a new UN mandate is needed to implement an independence plan drawn up by Martti Ahtisari, the Finnish UN envoy.