A letter by United Nations Secretary General Ban Ki-moon announcing plans to "reconfigure" the UN Mission in Kosovo (UNMIK) to accommodate an additional, European Union mission, was passed to presidents of Kosovo and Serbia on Thursday, according to dpa. "We're reconfiguring in the light of the situation on the ground," a diplomat in Pristina told Deutsche Presse-Agentur dpa. Kosovo President Fatmir Sejdiu was expected to reveal more details amid legal and diplomatic uncertainty how the UN would downgrade its role to allow local authorities and a new, European Union mission more power, but his briefing was cancelled without explanation. International officials in Pristina said Ban's letters were seen as a blow to Kosovo leaders, because of an aim to keep the UN mission on the ground in spite of Pristina's expectations and in line with Serbian demands. Earlier media reports said UNMIK, which took charge in Kosovo after NATO ousted Serbian forces in 1999, would downsize by 70 per cent after Kosovo passes its first sovereign constitution Sunday, four months after its unilateral declaration of independence. Helping Kosovo and its 90-per cent Albanian majority along its first independence steps is the EU law-enforcing mission, EULEX, which is to take over some of the functions from UN, with others transferred to Kosovo institutions. UNMIK is to remain longer in Serb enclaves, the largest of them on a quarter of Kosovo's territory in the north, where the local population joins authorities in Belgrade in opposing the presence of EULEX, arguing that Kosovo is Serbian soil. Serb protests against Kosovo's declaration of independence have turned violent in the northern Mitrovica enclave, claiming the lives of one Ukrainian policeman and a Serb protester. Another letter by Ban was sent to Belgrade and President Boris Tadic, who did not comment it. He was due to attend a regional conference in Athens on Friday. Changes to UNMIK and the arrival of EULEX have no effect on the NATO-led peacekeeping mission in Kosovo, the mission commander, General Xavier Bout de Marnhac, said. "The reconfiguration ... doesn't change the KFOR mandate much, we're are still under (UN resolution 1244)," he said. "Now we have to see how to settle things for the next stage. I know the letter arrived, but haven't seen it yet." In fact, NATO defence ministers meeting Thursday in Brussels expanded the mandate of the 15,700 troops to include training Kosovo's future security forces in addition to peacekeeping. Attached to Ban's letters was a longer report on his plan, which would be debated by the UN Security Council at the end of next week.