NEW YORK - The United Nations chief said he plans to give more authority to the European Union over police, courts and other official duties in Kosovo.

Secretary General Ban Ki-moon's decision, detailed in a report Thursday to the Security Council, comes after nine years UN administration of the disputed territory and just before Kosovo is to adopt a new constitution on Sunday.

The proposed constitution is strongly opposed by Russia, Serbia's traditional ally, which on Thursday called for the dismissal of the top UN official in Kosovo, Joachim Ruecker. Security Council veto-wielding Russia accused him of taking steps to reduce the UN mission there without authorization by the 15-nation council.

Russia backs Serbia and opposed steps toward independence for Kosovo, including the UN's handover of responsibility for security to the EU, which has forced the UN to remain in Kosovo.

Russia has said it considers the 2,200-strong EU mission to be illegal because it has not been approved by the other four veto-wielding members -- the United States, France, Britain and China -- and the rest of the council.

The disagreement over Kosovo's statehood has sparked fears of tensions spilling over in the troubled Balkan region.

"I believe that the United Nations is confronting a new reality in Kosovo, with operational implications" for the UN mission in Kosovo that it must take into account, Ban said in his report. "Not doing so could lead to increased tension with Kosovo, including between Kosovo's communities."

In his report, Ban said he intended to "reconfigure the international civil presence" in Kosovo, which declared independence in February, "in keeping with the European Union's expressed willingness to play an enhanced operational role in Kosovo in the area of the rule of law."

Ban said the European Union is ready to put staff on the ground in Kosovo in the areas of police, justice and customs and Kosovo will tolerate a continued United Nations presence in Kosovo provided that it only carries out "limited, residual tasks."

Council members were still studying Ban's plan, said U.S. Ambassador Zalmay Khalilzad, this month's council president.

Kosovo's Prime Minister, Hashim Thaci, has said it is Kosovo's goal to be a member of the European Union and NATO. Kosovo's Serb minority has shunned Kosovo's declaration of independence and threatens to set up its own assembly in Kosovo's Serb-dominated north, which borders Serbia.

An independent Kosovo has been recognized by 42 UN-member nations, including the U.S., Japan and Canada. Kosovo came under UN and NATO administration after a NATO-led air war halted former Yugoslav leader Slobodan Milosevic's crackdown on ethnic Albanian separatists in 1999. Serbia, which considers the territory its historic and religious heartland, has rejected Kosovo's statehood as illegal.

Ban also sent letters Thursday outlining his plans to Kosovo's president, Fatmir Sejdiu, and his Serbian pro-Western counterpart, Boris Tadic, who has called Kosovo's declaration of independence an illegal act.

The secretary general's recommendation could become "a tactical week-to-week chess game at which the Russians will be dogging the UN and EU at every step," said Alexander Anderson, of Brussels-based think tank International Crisis Group.