"Serbia's internationally recognized borders have been unilaterally violated," Vuk Jeremic told a news conference.
The U.S., Australia, and several leading European countries, including France, Italy and Germany have so far recognized Kosovo, while Russia, China and Spain have condemned the move.
He said Serbia would block Kosovo's admission to the UN, the Council of Europe and the OSCE and take unspecified political and economic action against states acknowledging its independence. He also indicated that Serbia's relations with countries recognizing Kosovo's independence could be jeopardized.
Kosovo authorities unilaterally declared independence on February 17.
The U.K. appointed its first ambassador to the self-proclaimed republic earlier on Wednesday a day after Serbs destroyed border posts between Serbia and the "world's newest state."
