A final round of talks between top Serbian and ethnic Albanian leaders on the future of Kosovo has ended without agreement in Vienna.

United Nations special envoy and chairman of the negotiations Martti Ahtisaari said the potential for negotiations had been exhausted.

He plans to present his ideas to the UN Security Council later this month.

The summit was seen as a last chance for two sides who remain very far apart to present their views on his plan.

"I regret to say that at the end of the day, there was no will on the part of the parties to move away from their positions," Mr Ahtisaari said.

"The parties' respective statements on Kosovo's status do not include any common ground."

Mr Ahtisaari backs a form of self-rule for Kosovo which stops short of full independence.

Ethnic Albanian politicians are broadly in favour of the blueprint, which gives Kosovo the trappings of a sovereign state, but Serbia strongly opposes the plan.

Diplomatic struggle

Serbian President Boris Tadic said the plan was "unacceptable" and "unbearable" and Prime Minister Vojislav Kostunica said it violated international law.

"Snatching Kosovo from Serbia would represent the most dangerous precedent in the history of the UN," Mr Kostunica told the closed-door meeting, according to remarks distributed to reporters.

He told reporters after the talks: "I appeal for negotiations to continue. This proposal does not meet the conditions to be presented to the UN Security Council."

Kosovan President Fatmir Sejdiu and Prime Minister Agim Ceku gave their broad backing to the document.

Mr Sejdiu told the meeting that independence was "the beginning and end of our position", Reuters news agency reported.

"This is the future of Kosovo, a modern state which came to fruition after a history of resistance to foreign occupation."

The talks marked the end of a year-long diplomatic process.

Once Mr Ahtisaari has presented his final plan to the UN Security Council at the end of March, it will then be up to the UN's highest body to decide whether to approve or reject his proposals.

This could be where the real diplomatic struggle begins, correspondents say.

Serbia wants veto-wielding Russia to stick to its long-held position that it will not accept a deal on Kosovo's status unless it is agreed by both sides.

But the BBC's Gabriel Partos says the US and EU countries argue that if the plan is blocked, Kosovo's overwhelmingly ethnic Albanian population could go ahead with a unilateral declaration of independence, which might lead to a chaotic situation and possibly violence.

Ethnic Albanians comprise some 90% of Kosovo's two million people.

The UN has administered Kosovo since a Nato bombing campaign forced out Serbian troops in 1999.

Photo caption

Kosova's President Fatmir Sejdiu (L) and Prime Minister Agim Ceku (R) at the Vienna talks