Kosovo won't be part of Serbia again-US State Dept

WASHINGTON, Feb 25 (Reuters) - Kosovo will never be part of Serbia again, the U.S. State Department said on Monday, but said Washington would keep working on the issue with Belgrade and its ally Russia, which both oppose independence.

State Department spokesman Tom Casey spoke after Russia's likely next president, Dmitry Medvedev, visited Belgrade to show Moscow's backing for Serbian sovereignty over Kosovo despite Western support for its declaration of independence.

"We are going to continue to try to work with both the Russians and the Serbs on this but I think that it ought to be clear to everybody at this point that Kosovo is never going to be a part of Serbia again," Casey told reporters.

In Belgrade, Serbia's Prime Minister Vojislav Kostunica said protest rallies against the new Kosovo republic would continue and there would be no normalization of ties with capitals which had accepted it until they changed policy.

Casey said the United States, which has recognized Kosovo's independence, had no problem with peaceful demonstrations over the matter, so long as they did not turn violent.

Last week, the U.S. embassy in Belgrade was attacked and set on fire by rioters angered by Kosovo's declaration of independence on Feb. 17 and U.S. support for the move.

Casey said family members and nonessential U.S. embassy personnel had left Belgrade until security there improved, but the U.S. ambassador, Cameron Munter, remained in the Serbian capital along with other U.S. officials.

Last week U.S. Secretary of State Condoleezza Rice blamed Serb authorities for failing to protect the embassy, and Serbia has expressed official regret for the incident.

Casey said all parties should move forward now with implementing a plan for Kosovo's supervised independence that was developed by U.N. envoy Martti Ahtisaari.

"We don't want to isolate Serbia," he said, adding that the United States wanted Serbia to be able to achieve ambitions to be a part of Europe. "We think that is the future of the country and we hope that is the direction its leadership wants to take it in." (Editing by David Storey)