Under Secretary of State for Political Affairs David Hale, who met with Serbian President Aleksandar Vucic, also called Friday on Kosovo to lift a 100-percent tariff on Serbian goods so that European Union-mediated talks can resume.
The call came a day after Kosovo's Parliament adopted a negotiating platform for the talks that involves mutual recognition and keeping the current borders intact. Serbia doesn't recognize Kosovo's independence, but the two have been told they must improve bilateral relations to join the EU, which has mediated negotiations aimed at resolving the long-standing Balkan dispute.
Kosovo declared independence from Serbia in 2008 after fighting a 1998-99 war that ended with NATO intervening to stop a bloody Serbian crackdown of Kosovo Albanian separatists. Serbian officials have said the rigid platform dashes all hopes for a compromise solution.
According to a statement issued by the Serbian president's office after the meeting, Vucic told Hale that Kosovo's platform "amounts to a decision by Pristina to halt dialogue with Belgrade" because it leaves no room for compromise.
In a strongly-worded speech later on Friday, Vucic described Kosovo's negotiating platform as an "ultimatum" aimed at "humiliating Serbia." "I will never agree to that," Vucic told his supporters in a northwestern Serbian town. "With those who don't want the talks, there are no talks and there will be no talks."
Although never made official, Vucic is thought to be seeking changes, or "corrections," of Kosovo's borders as part of an overall agreement — something not welcomed by many EU states. Angered by the Kosovo platform, Vucic on Friday summoned top Serbian political and security officials to mull what to do next.
Serbian Prime Minister Ana Brnabic said after the meeting that the Kosovo position represents "a death blow" to the talks and that Serbia's reaction will be "moderate and in the interest of our citizens."
"That document is against any compromise and dialogue," Brnabic said. "It is against common sense." Serbia had previously said it will not take part in the EU-facilitated discussions until the 100-percent tax is ditched, while Kosovo wants Serbia to recognize its statehood and stops preventing it joining international organizations such as International Police, or Interpol.
Llazar Semini contributed from Tirana, Albania.