US Secretary of State Hillary Clinton on Wednesday said that Kosovo's unilaterally declared independence, fiercely opposed by Serbia, was not debatable.

"(The United States) 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.

Washington is one of the main supporters of Kosovo's independence, 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 and Kosovo Serbs.

Clinton also said that the US wants to see the rule of law "extended throughout Kosovo", in a reference to majority-Serb northern Kosovo where the ethnic Albanian authorities have no influence and Serbia maintains parallel institutions.

Clinton will hold talks with Kosovo leaders Wednesday to urge them to step up efforts for EU and NATO integration in order to secure peace in the volatile Balkans region.

Clinton, together with EU foreign policy chief Catherine Ashton who has joined her on part of her five-nation regional tour, is expected to urge Kosovo to continue EU-brokered talks with Belgrade.

The pair were due to meet President Atifete Jahjaga and Prime Minister Hashim Thaci Wednesday morning.

Kosovo's Zeri newspaper said that Clinton's visit confirms "the message that Kosovo is an independent country and that is a closed chapter."

It also proved "that any political process in the region cannot get moving without the presence and support of the United States," the paper said.

Prior to the visit, Thaci told his cabinet Pristina expects "strong support" from both Washington and Brussels for its "integration into NATO, EU and UN".

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, 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.

Washington's support for the dialogue could boost public support as US officials, notably former president Bill Clinton, are seen as key supporters for Kosovo's bid for independence from Serbia.

In 1999, then president Clinton ordered US forces to take part in the NATO bombing campaign that drove Serb troops under the command of late strongman Slobodan Milosevic out of Kosovo.

His bronze statue graces central Kosovo's Bill Clinton boulevard.

"It is very important to be careful about the dialogue. I do not believe Belgrade means us well, but if our American friends say we should take part in it, we should," 29-year-old shop assistant Hajrije Mjekiqi told AFP.

Talks between Belgrade and Pristina were launched in March 2011 under EU auspices but were suspended for several months after elections in Serbia in May that were won by nationalists.

Brussels has stressed that progress in the talks is a key factor if Serbia, which won EU candidate status in March, is to move forward and open full accession talks.

The talks are 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.

Clinton came to Kosovo from Serbia, where on Tuesday she pushed Belgrade to normalise relations with Kosovo, even without recognising the independence of the breakaway territory.

"The United States urges all parties to implement the agreements reached to date (in the EU-brokered talks between Belgrade and Pristina), and to advance concrete measures to normalise relations," Clinton said, adding that the dialogue  "does not require Serbia to recognise Kosovo".

From Kosovo Clinton travels to Croatia -- due to become the EU's newest member in July next year -- and Albania. Both joined the NATO transatlantic military alliance in 2009.

Of the six ex-Yugoslav republics, only Slovenia has joined the European Union in 2004.