Kosovans have been keen to show their appreciation of the US
US Vice-President Joe Biden has told Kosovo's parliament its independence is "absolutely irreversible" and the only viable option for regional stability.
"The success of an independent Kosovo is a priority for our administration," Mr Biden said in a speech that received several standing ovations from MPs.
Earlier, he received an enthusiastic welcome from crowds of ethnic Albanians in the capital, Pristina.
However, the Serb minority said it was planning to hold anti-US protests.
The US played a leading role in the Nato bombing campaign which expelled Serbian forces from Kosovo a decade ago.
On the final stage of his three-day tour of the Balkans, Mr Biden became the most senior US official to visit Kosovo since it declared independence in February 2008.
The US and more than 50 other countries have recognised its independence, but more than 100 have not, including Serbia and Russia.
"Kosovo's independence was and remains today in my view, in the view of my government, the only viable option for stability in the region," he told a special sitting of the parliament in Pristina.
"And your independence - as I've said in the countries I have visited - your independence, is irreversible, absolutely irreversible," he added to applause from the ethnic Albanian-dominated assembly.
Earlier, after holding talks with President Fatmir Sejdiu, Prime Minister Hashim Thaci and other leaders, Mr Biden said he had been awarded the Golden Medal of Freedom, Kosovo's highest honour.
"I don't deserve it, but I received it on behalf of the United States," said the vice-president, who many Kosovans credit with helping them gain independence while he was a senator.
Earlier, thousands of schoolchildren waved US flags along the route his motorcade took from Pristina airport, while posters lined the route declaring "Welcome, and thank you".
His reception contrasted markedly with that in his previous stop, Serbia, where police lined the streets amid nationalist anger.
MPs from the hardline nationalist Serbian Radical Party held up banners in parliament saying: "Biden, you Nazi scum, go home."
Mr Biden said he did not expect Serbia to recognise Kosovo's independence
Serbian President Boris Tadic told Mr Biden on Tuesday that his country would never give up its claim to Kosovo.
But despite that outstanding issue, and the antipathy of many Serbs to the US because of the Nato bombing campaign in 1999, Mr Biden and the pro-Western Mr Tadic exchanged warm words.
Mr Biden said: "The United States does not, I emphasise, does not expect Serbia to recognise the independence of Kosovo."
"It is not a precondition for our relationship or our support for Serbia becoming part of the European Union," he said.
Mr Tadic said Serbia and the US could move their relationship forward "on the basis of dialogue rooted in mutual respect".
The rare visit by a top US official marks a new effort by President Barack Obama to re-engage with the Balkans, BBC Eastern Europe correspondent Nick Thorpe says.
As well as Serbia and Kosovo, he has also visited Bosnia-Hercegovina.