BELGRADE, Serbia-Serbia urged the return of its army and police to Kosovo, an official said Friday, a move that could increase ethnic tensions in the breakaway province.

"The time has come for the return" of some 1,000 Serbian security personnel to the province, said Aleksandar Simic, a spokesman for Prime Minister Vojislav Kostunica. In Kosovo, 90 percent of the 2 million people are ethnic Albanians.

The U.N. administration in Kosovo refused to comment before it gets a formal request from the Serb government for the troops' return.

Under a U.N. Security Council resolution passed in 1999 when NATO troops chased out Serbian security forces from Kosovo after their crackdown against Kosovo Albanian separatists, Serbia was granted the return of up to 1,000 police and army troops to the province's borders and to guard Serbian churches and monasteries there.

But NATO and U.N. peacekeepers in Kosovo have not allowed the redeployment, fearing it could irritate Kosovo Albanians and re-ignite violence and ethnic tensions in the tense region.

Kosovo, considered by many Serbs as the cradle of their statehood and religion, is only formally a part of Serbia. The province has been run by the United Nations and NATO since 1999, when NATO launched an air war to halt Serbia's government onslaught on Albanian separatists.

Last week, envoys from the United States, the European Union and Russia launched a 120-day effort to end the impasse over Kosovo. A new round of talks has been set for Aug. 30 in Vienna, Austria.

Simic said that the return of the Serbian troops to Kosovo is a "precondition" for a possible deal with ethnic Albanians.

The new negotiation effort follows Russia's threat to block a U.S.-backed plan to grant Kosovo internationally supervised independence in the U.N. Security Council. The diplomats are to report back to U.N. Secretary-General Ban Ki-moon by Dec. 10.