Serbia asked NATO on Saturday for permission to send troops back to Kosovo, nearly four years after the alliance bombed Serb forces to oust them from the province, if there is a war in Iraq.

Serbian Prime Minister Zoran Djindjic said Serb troops would fill any security vacuum in Kosovo if NATO withdraws troops for military action in Iraq. However, no plans have been announced to reduce the number of troops in the peacekeeping force because of the current Iraqi crisis.

Kosovo has been administered by the United Nations since 1999, when NATO fought an air war to end then-Yugoslav President Slobodan Milosevic's crackdown on the province's independence-minded ethnic Albanians. A NATO-led peacekeeping force of 30,000 troops is stationed in Kosovo, which remains part of Yugoslavia.

Wing Cmdr. Tony Adams, a spokesman for the NATO force, said the number of troops could be reduced by about half by December if security in the province continues improving.

Adams said he could not respond to Djindjic's request to send 1,000 troops but added, "We have no requirement nor necessity for forces other than the (NATO-led) Kosovo Force to operate in Kosovo."

Ramadan Avdiu, a senior adviser to Kosovo's Prime Minister Bajram Rexhepi, criticized Djindjic's request.

"Any tendency to return those forces in Kosovo is an attempt to destabilize Kosovo and the entire region," he said.

Serbia wants to retain control over Kosovo, while the province's mostly ethnic Albanian population is pushing for independence.

Kosovo still is plagued by scattered violence and most of the 230,000 Serbs and other non-Albanians who fled the province have not been able to return. The Serbs who remain live in isolated enclaves, protected by peacekeepers.