PRISTINA, Serbia (Reuters) - The United Nations must not allow snap elections in Serbia to delay a decision on the fate of Kosovo, the province's ethnic Albanian leaders said on Wednesday.

U.N. mediator Martti Ahtisaari told Finnish television on Tuesday that if Serbia calls a general election for late December, he could put back his proposal, widely expected to back Kosovo's demand for independence.

But the Kosovo government, which is promising 2 million impatient ethnic Albanians their own state as of Jan 1, said Serbian polls "must not have any impact on the status process."

"They are an internal Serbian issue," Arben Qirezi, senior advisor to the prime minister, told Reuters.

"We are working toward a status resolution within the timeframe set by the Contact Group, and that is within the year," Qirezi added.

The United States and major European powers had insisted on a deal in 2006, concerned that delay could spark fresh violence in a territory patrolled by 16,000 NATO-led troops.

Finland's Ahtisaari was expected to make his proposal by November. But with Vojislav Kostunica's Serbian government on the ropes over suspended European Union talks and headed for early elections, Ahtisaari said the six-member Contact Group of major Western powers and Russia might tell him to wait.

"If the election date will be at the end of this year, it might be that in the Contact Group there is a will to reconsider the timetable and maybe it will mean that my proposal, which is under preparation, would be presented only after the elections," Ahtisaari told Finland's public broadcaster, YLE.  

Kosovo has been run by the United Nations since 1999, when NATO bombs drove out Serbs forces accused of civilian killings and ethnic cleansing in a two-year war with guerrillas. Ninety percent of its people are Albanians, who lost 10,000 to the war.

Ahtisaari opened direct talks in February in Vienna, but there has been no compromise on the central issue of Kosovo's future status. The U.N. Security Council looks certain to impose a solution, which diplomats say will bring a form of independence supervised and policed by the EU.

Diplomats say at least several weeks, perhaps months could pass between Ahtisaari's proposal and a U.N. vote.