Serbia does not recognize Kosovo's independence and has vowed to maintain its control in Serb parts of its former province.
Serbia's official Tanjug news agency says Belgrade's electoral commission adopted a resolution late Wednesday confirming plans to organize the May 11 vote in Serb-inhabited areas of Kosovo.
The new Kosovo government in Pristina has not responded publicly to the reports. But the head of the U.N. mission in Kosovo told British radio the world body will not recognize election results.
Local U.N. mission chief Joachim Ruecker said the Serbian decision violates the U.N. mandate for overseeing Kosovo's political and military affairs. But he said his agency will not move to stop the polls.
Kosovo and its 90 percent ethnic Albanian majority declared independence from Serbia February 17. More than 30 nations have offered recognition, including the United States and many European governments. Belgrade has responded by withdrawing its ambassadors from those countries.
NATO airstrikes in 1999 drove Serb forces from Kosovo, which has since been administered by the United Nations.