Kosovo's parliament is set to vote Dec. 14 on transforming the country's security forces into a regular army. Serbian officials claim the army would be used against the Serb minority in Kosovo, which declared independence in 2008.
Serbia has threatened unspecified retaliatory measures if the army is created. Serbia, Russia and China don't recognize Kosovo as a country, while the United States and most of the West do.
Serbian President Aleksandar Vucic met separately with the Russian, Chinese and U.S. ambassadors in Belgrade on Tuesday, saying that "continuous provocations" from Kosovo could leave Serbia with no choice but to "protect" the Serb minority.
Vucic said Kosovo's plans to form an army jeopardize peace and stability in the region.
"The irresponsible behavior of Pristina could lead into a catastrophe because Serbia cannot peacefully watch the destruction of the Serbian people," Vucic said in a statement.
Tensions between Serbia and Kosovo soared after the Kosovo government last month introduced a 100-percent tax on Serb imports - an apparent retaliation for a failed Kosovo bid for membership in the international police organization, Interpol, after intense Serbian lobbying.
Vucic said it's "completely clear" that both the formation of the army and the tariffs are intended to "force Serbs out" of Kosovo.
Kosovo split from Serbia after a 1998-99 war for independence that left more than 10,000 dead. Serbia's brutal crackdown in the province prompted NATO to launch airstrikes to stop the conflict.
An armed intervention by Serbia in Kosovo would trigger a direct clash with NATO-led peacekeepers stationed there. Serbia recently increased its saber-rattling, including raising the combat readiness of its troops over a series of small incidents.
Meanwhile, Kosovo police stopped a Serbian basketball team from entering the country. They were to attend a daily protest by Kosovo Serbs against the 100-percent tariffs on Serbian goods.
Llazar Semini contributed from Tirana, Albania.
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