Vuk Jeremic did not specify how Serbia would respond if separatist Kosovo Albanian officials carry out their threat to declare independence if a final push for a diplomatic settlement between now and Dec. 10 does not result in the Serbian province's statehood.
"Serbia will have no choice but respond to the acts which would jeopardize its sovereignty and territorial integrity," Jeremic said. "The unilateral declaration of independence would bring protracted instability to the region," he warned.
But, Jeremic also said that Serbia would not allow itself to be plunged back to international isolation as during the rule of late President Slobodan Milosevic in the 1990s.
Diplomats from the United States, European Union and Russia are trying to get the two sides to agree on Kosovo's political future, eight years after NATO airstrikes were launched to stop a Serbian crackdown against separatist Kosovo Albanians.
Since then the province has been under U.N. and NATO control, although it is formally still part of Serbia.
Kosovo Prime Minister, Agim Ceku, reiterated Friday that the province's leaders would declare independence if no agreement was reached during the talks, which opened Thursday in Vienna, Austria. But no unilateral move would be made without support from the U.S. and EU, he said.
Nationalist Serbian Prime Minister Vojislav Kostunica said Thursday that in case Kosovo declares independence without consent from the U.N. Security Council - where Serbia's ally Russia has a veto power - Serbia "would have to respond with damage against damage."
He also did not specify what he meant, but Serbian ultranationalists have even called for military action against Kosovo Albanian separatists in case they declare independence of the province, which Serbs consider the cradle of their statehood and religion.
Kostunica has indicated Serbia would cut off diplomatic ties with all countries that recognize such unilateral declaration. The United States has hinted it would recognize Kosovo's statehood even without a U.N. approval, while the EU states were split over the issue.
Germany's visiting defense minister, Franz Josef Jung, appealed Friday for calm in Kosovo, after a latest round of talks to settle the future of the disputed province failed to bridge differences between ethnic Albanians and Serbia.
Jung urged all sides to avoid violence that would hamper the current internationally brokered negotiations. So far both sides have refused to back down from their political demands, with ethnic Albanians seeking independence, while Serbia wanting to keep at least formal control over Kosovo.
"I ask all sides for restraint," Jung told reporters. "We are making all efforts for these talks to end by December and to avoid turmoil that would hinder the talks."