THE HAGUE (Reuters) - Kosovo’s 2008 declaration of independence was the only viable option after brutal ethnic cleansing in the Balkans, the United States told the World Court on Tuesday, countering Russia’s argument that former ruler Serbia no longer posed a threat to Kosovo.

An ethnic Albanian boy rides a bicycle past paintings of the flags of countries who supported Kosovo's independence, in Gnjilane February 19, 2008. REUTERS/Damir Sagolj

The International Court of Justice (ICJ) is holding hearings examining whether Kosovo’s declaration of independence was legal, following objections raised by Belgrade. After two weeks of hearings that end this week, the court is expected to deliver an advisory and non-binding ruling in a few months.

The United States told the U.N. court that Kosovo’s secession was the “will of the people” and resulted from the failure of Serbia and Kosovo to reach a political solution after their 1998-99 war.

Kosovo’s necessary declaration “brought much-needed stability to the Balkans and closed the book on the protracted break-up of what was Yugoslavia,” said Harold Hongju Koh, legal adviser to the U.S. Department of State.

The ICJ hearings come a decade after separatist Kosovo Albanians triggered a crackdown by the Yugoslav army and police, which ended after a 78-day NATO bombing campaign against Yugoslavia in 1999.

Russia told the court Kosovo was no longer under threat and that events of 10 years ago -- which led the U.N. Security Council to adopt a resolution to secure a ceasefire and Kosovo self-governance -- could not serve as a basis for independence.

“By 2008, there was clearly no threat to the population of Kosovo coming from the Serbian authorities and there were clearly full chances for a negotiated solution for a truly self-governing Kosovo within the state of Serbia,” said Kirill Gevorgian, Russia’s ambassador to the Netherlands.

Kosovo’s declaration has been recognized by 63 states, but Serbia -- which has said Kosovo is its historical cradle -- and its ally Russia have refused to do so, arguing it was not in accordance with international law.

Russia has largely subdued a separatist Islamist insurgency in its province of Chechnya, but recognized Georgia’s breakaway regions of South Ossetia and Abkhazia as independent states last year, a move only two other countries -- Nicaragua and Venezuela -- have copied.

EUROPE’S FUTURE

Koh, citing the U.S. declaration of independence, said not one of more than 100 such declarations globally has ever been ruled to have violated international law. He urged the court to rule in favor of Kosovo or refrain from giving any ruling.

“Kosovo is now independent and both Serbia and Kosovo are part of Europe’s future,” he said, stressing the United States had come to the court as a friend of both parties.

Kosovo said last week its independence was irreversible and was made necessary by Serbia’s killing of 12,000 of its people in the 1990s.

But Serbia said its declaration flagrantly violated its territorial integrity, and its lawyers warned the case was being watched anxiously by other countries with separatist problems.

Spain, grappling with its own separatist movements, agreed human rights abuses should be taken into account when considering Kosovo’s future, but said it could not identify a new offence that could justify “remedial secession.”

The Basque separatist movement ETA has killed more than 800 people in four decades in its fight for an independent state in northern Spain and southwestern France. Spain is one of five EU member states that have not recognized Kosovo as independent.

Permanent Security Council member China argued on Monday the U.N. Security Council resolution reaffirming commitment to the territorial integrity of Yugoslavia was binding, and Kosovo and Serbia should negotiate a settlement acceptable to both parties.

“Only by doing so could they reach a fair and reasonable outcome and a lasting peace be established in the Balkans,” said Xue Hanqin, legal counsel to China’s Foreign Affairs Ministry. China brands Tibet’s Dalai Lama a separatist, although he says he only wants more autonomy for the region, and also faces a breakaway movement in its northwestern Xinjiang region.