Pristina: US Secretary of State Hillary Clinton on Wednesday said that Kosovo’s unilaterally declared independence, fiercely opposed by Serbia, was not debatable and urged their leaders to show “courage”.

“We will oppose any discussion of territorial changes or reopening Kosovo’s independent status. These matters are not up for discussion,” she said, reiterating Washington’s strong support for Kosovo’s ethnic Albanian authorities on a visit to Pristina.

The disputed status of Kosovo is the main bone of contention still affecting regional ties after the break-up of the communist former Yugoslavia, which collapsed in a series of bloody wars in the 1990s.

After meeting with Kosovo President Atifete Jahjaga and Prime Minister Hashim Thaci, Clinton told reporters that European Union membership — dependent on improved ties between Kosovo and Serbia — offered “the surest path to long-term stability, prosperity and peace”.

EU-brokered talks that stalled after Serbian elections in May had been meant to ease daily life for the inhabitants of Kosovo, ethnic Albanians and Serbs alike, who face many administrative hurdles because of the disputed status of the territory.

“The United States urges all parties to continue to work to implement the agreements reached to date, reach agreements in new areas, and advance concrete measures to normalise relations,” Clinton said.

“It calls for political will, even courage, but by moving forward on this path Kosovo and Serbia will be aided in their efforts to tackle other urgent matters like strengthening their economies and creating opportunities for their people,” she added.

Kosovo could take a first step towards joining the EU in the first half of 2013 if it makes solid progress in the rule of law, protection of minorities and other political reforms.

Washington is one of the main supporters of Kosovo’s independence, which it unilaterally proclaimed in 2008.

It is recognised by some 90 states including 22 of the European Union’s 27 members but is rejected by Serbia.

Many ordinary Kosovans are still wary of any negotiations with arch foe Serbia and Kosovo saw violent protest last week after Thaci met his Serbian counterpart Ivica Dacic in Brussels to re-launch the talks.