Krstimir Pantic, deputy director of the Government Office for Kosovo and Metohija, said "Serbia is done with making concessions," B92 reported Monday.
"We have reached the red line, anything more than this would mean an indirect recognition of Kosovo as an independent state," said Pantic.
The official said Serbian President Tomislav Nikolic wants nations who have recognized Kosovo as an independent country to "appreciate" Serbia's position and push the government in Pristina to compromise.
Pantic accused ethnic Albanians in Kosovo seeking to establish statehood for the province of "putting up a wall" in negotiations.
"The Albanians must renounce some of their wishes," he said.
Pantic said the new government refused to make "a single deal" except for agreeing to collect taxes and fees on goods entering Kosovo from Serbia.
Serbia wants the money collected used for development of four Serb cities in northern Kosovo, but the Albanians want the funds to go into the Kosovo budget, he said.
Ethnic Albanians in Kosovo unilaterally declared Kosovo an independent country in 2008. The two sides have been negotiating since March 2011 in talks sponsored by the European Union.