The Associated Press

BELGRADE, Serbia—Serbia’s newly re-elected president Boris Tadic pledged at his inauguration Friday that he would never stop fighting against independence for Kosovo.

Kosovo’s Albanian leadership is planning to unilaterally declare independence within days. But Serbia has vowed never to accept statehood for the breakaway province.

Although Kosovo is technically part of Serbia, the impoverished province of two million people has been administered by the United Nations since a brief war in 1999.

After a series of negotiations on the final status of the province failed to produce a compromise, ethnic Albanians—who make up 90 percent of the Kosovo’s population—are planning to unilaterally proclaim independence in the next several days.

On Thursday, Serbia’s government adopted a resolution declaring any unilateral act by Kosovo’s ethnic Albanian leadership to be invalid and illegal. And Tadic said Friday the country would downgrade, but not break, diplomatic relations with any government that recognizes an independent Kosovo.

The increasingly heated rhetoric by Serbian leaders appeared designed to increase pressure on foreign governments to deny recognition to an independent state.

Serbia’s nationalist Prime Minister Vojislav Kostunica lashed out Friday at Western nations that have backed Kosovo’s bid for independence.

“Throughout history, many oppressors have tried to forcibly wrench Kosovo from us, but this is the first time (they) are demanding that we accept this in a slave-like manner,” Kostunica said in a clear reference to the United States, and many European nations that have supported Kosovo’s ethnic Albanians.

Kosovo’s declaration of independence is strongly supported by the United States and most members of the European Union, who view it as the final stage in the breakup of the old Yugoslav federation.

But Serbia maintains it would constitute a violation of the U.N. Charter that calls for respect of territorial integrity of member states.

State Department spokesman Sean McCormack said that the United States would continue to encourage Tadic’s aspirations to integrate Serbia more closely with Europe, despite the disagreement over Kosovo.

Serbia has traditionally regarded Kosovo, the site of its first medieval kingdom, to be its historic heartland. Over the centuries it was occupied by the Ottoman Turks, the Austro-Hungarian Empire and fascist Italy during World War II, but it always reverted to Serbian rule.

The Serbian government has adopted a secret “Action Plan” to be implemented when Kosovo declares independence. It is believed to include retaliatory steps to encourage the province’s 130,000-strong Serb minority to shun the declaration and formally keep their territories under Serbian control.

Russia and some other members of the U.N. Security Council also oppose Kosovo’s statehood, calling it a dangerous precedent to set for separatists worldwide.

Tadic and his prime minister, Kostunica, both pledge not to recognize Kosovo’s secession. But unlike Kostunica, Tadic advocates Serbia’s integration into the EU despite the bloc’s support for Kosovo’s independence.

In his inaugural oath before Serbian deputies, Tadic pledged to pursue Serbia’s European future.

“I will fight with full force to achieve Serbia’s membership in the European Union,” he said.

Kostunica, a conservative nationalist, blasted the EU in a speech to mark the 204th anniversary of the modern Serbian nation. He said the EU was making Serbia’s accession to the bloc contingent upon acceptance of Kosovo’s independence.

“(They want) us to join the European family as the only nation that gained its seat at the table through an indecent trade, by giving up our identity,” Kostunica said.

Tadic, a pro-Western reformist, narrowly won a Feb. 3 runoff against his ultra-nationalist challenger Tomislav Nikolic. The vote was seen as crucial for Serbia’s future, offering a choice between Tadic’s pro-EU policies and Nikolic’s pro-Russian nationalism.