On Tuesday, the UN Security Council discussed a plan on the status of Kosovo, which has a population of two million made up primarily of an ethnic Albanian majority and a 150,000-strong Serbian minority.
Proposed by Marti Ahtisaari, a special UN envoy for the talks on Kosovo, the plan to grant the province internationally supervised sovereignty has been strongly opposed by both the Serbian minority in Kosovo and the government of Serbia.
It received the support of only four of the 15 UN Security Council members during the first round of talks.
"Serbia will not accept Kosovo's independence and will fight for its sovereignty and territorial integrity by all legal means," Tadic told Russia's Vesti-24 television channel.
Kosovo has been a UN protectorate since NATO's 78-day bombing campaign against the former Yugoslavia ended a war between Serb forces and Albanian separatists in 1999.
The president said Serbia highly estimated Russia's position in principle, which he said respected not only the sovereignty of Serbia as a UN member but also protected international law and the interests of global order.
Veto-wielding Russia has opposed the internationally backed plan, insisting that a decision on Kosovo should satisfy both Kosovar and Serbian authorities and that it must be reached through negotiations.
When asked whether Serbia is ready for the possibility of Kosovo's unilateral declaration of its independence, Tadic said that such a decision would be dangerous for the whole world and its stability.
"This would be a precedent that would entail an unpredictable process enabling any ethnic group in any country to demand independence," he said.
Tadic's words echo Russia's position that granting Kosovo sovereignty would set a precedent for the breakaway regions in the former Soviet Union Moscow is believed to support - Georgia's Abkhazia and South Ossetia, and Moldova's Transdnestr.
Commenting on the assumption that the West could offer Serbia a kind of deal, namely to endorse Ahtisaari's plan in exchange for EU accession, Tadic said that neither he nor anyone in the Serbian government had received a proposal of the sort.
"Such an exchange is unacceptable to us. We want to join the EU, but we hope the EU will be reasonable enough not to make this contingent on our position on the status of Kosovo," Tadic said.