Kosovo's independence has provided a tool kit for secessionist movements in Europe and beyond, Serbian Foreign Minister Vuk Jeremic has said.
He also said recognition of Kosovo by some EU members would jeopardise Serbia's path to EU membership.
His remarks came as Nato troops reopened Kosovo's northern borders, closed after the demolition of two border posts by Serbian protesters.
Correspondents say the situation at the border is currently calm but tense.
Nato peacekeepers reopened the two demolished border checkpoints on Wednesday.
Crowds of demonstrators had used bulldozers and explosives on Tuesday to demolish the border posts at Jarinje and Brnjak, and peacekeepers were called in to restore order.
Nato commander Xavier Bout de Marnhac was quoted as blaming local Serbian leaders for the trouble.
Students in the Serb-dominated town of Mitrovica are organising daily protests at 12.44 pm, referring to UN Security Council resolution 1244 under which Serbia insists it still has sovereignty of Kosovo under international law.
Mr Jeremic said Kosovo's declaration of independence was illegal and illegitimate, adding that Serbia would fight tooth and nail to have it overturned.
Speaking at the Council of Europe in Strasbourg, he said those who had recognised Kosovo had set a dangerous precedent.
"By the actions of some European member-states, every would-be ethnic or religious separatist across Europe and around the world has been provided with a tool kit on how to achieve recognition," he said.
"Does anyone in this room think that the Kosovo Albanians are the only group in the world with a grievance against their capital?"
Some Russian officials have hinted that Moscow could recognise the Georgian breakaway regions of Abkhazia and South Ossetia in response to the Kosovan declaration.
Mr Jeremic also said Serbia's path to full EU membership had been damaged by the recognition of Kosovo by more than half the EU's member countries.
"The relations between Serbia and certain members of the European Union have been compromised and I don't see how we can accelerate our efforts towards Europe," he said.
Many - though not all - EU states have argued that Kosovo is a unique case - that Serbia lost its right to govern there because of the brutal repression of the Albanian majority.
Earlier EU special envoy Pieter Feith began his work in Pristina as the head of the international civilian office due to take over from the UN.
STANCE ON RECOGNITION
For: Norway, Denmark, Finland, Sweden, Germany, Italy, France, UK, Austria, US, Turkey, Albania, Afghanistan
Against: Russia, Spain, Romania, Slovakia, Cyprus
He insisted that a 2,000-strong EU police and justice mission would be deployed throughout Kosovo despite Serb hostility.
But Russian Foreign Minister Sergei Lavrov said the mission was "in breach of the highest international law".
In a separate development, the German cabinet agreed formally to recognise Kosovo's independence. Norway also announced its intention to accept Kosovo as an independent state.
But Serbia responded by recalling its ambassadors to Germany and Austria, another country that has recognised Kosovo.
Britain, France, and Italy were among the first to come out in favour of Kosovo's independence but other EU countries are opposed.
The UN Security Council is divided over how to respond to Kosovo's move, and it has failed to agree on any action.
Serbian security forces were driven out of Kosovo in 1999 after a Nato bombing campaign aimed at halting the violent repression of ethnic Albanian separatists.
The province has been under UN administration and Nato protection since then.