By Matt Robinson
BELGRADE (Reuters) - Serbia's prime minister threatened on Friday to pull out of EU-mediated talks with Kosovo after the former Serbian province denied him permission to visit, underscoring the fragility of a landmark accord between the two.
Ivica Dacic lashed out at the European Union, which is expected to open accession talks with his country in January in part as a reward for the April accord with Kosovo, which seceded in 2008 in the last act in the break-up of former Yugoslavia.
Dacic negotiated the deal with his Kosovo counterpart, Hashim Thaci, in months of delicate talks in Brussels, agreeing for Serbia to renounce its de facto hold over a small Serb-populated pocket of majority-Albanian Kosovo.
NATO waged an air war to drive Serbian forces out of Kosovo in 1999 and stop ethnic cleansing after negotiations failed to halt a conflict that was destabilizing the Western Balkans.
Under the April deal, the northern Serb pocket is slated to take part in a Kosovo municipal election on November 3.
Dacic had planned to visit minority Kosovo Serbs on Friday to encourage them to take part in the vote, but the government in Pristina said he would be refused access for the duration of the election campaign.
"We in government, in the interest of the state, we risked our lives and careers and now someone wants to humiliate us with such a decision," Dacic told a news conference, saying the ban represented a violation of the April accord.
"If the European Union finds that normal, then I no longer have any interest in taking part," he said.
EU foreign policy chief Catherine Ashton is due to host Dacic and Thaci again on Monday to discuss implementation of the accord, which faces resistance from northern Kosovo Serbs.
"I won't allow anyone to humiliate me," said Dacic. "Let them find someone else to negotiate with. I hope this won't be my last trip to Brussels for talks, but if it is, I won't exactly miss it."
Without implementation of the Kosovo agreement, the start of EU accession talks with Serbia could be thrown into doubt.
Serbia hopes membership talks, which will likely run to around 2020, will drive reform and lure foreign investment to the biggest of the seven countries carved from socialist Yugoslavia when it collapsed in the 1990s.
Serbian media had initially reported a blanket ban by Kosovo on Serbian officials visiting during the election campaign, but Vlora Citaku, Kosovo's European Integrations Minister, said there had been a "misunderstanding".
"There was no ban for Serbian officials to visit Kosovo!" Citaku wrote on Twitter late on Thursday. "There was just a No for Dacic visit! That's all!"
Asked about the spat, a spokeswoman for the EU's Ashton said: "We expect Prime Minister Dacic and Prime Minister Thaci on Monday in Brussels to discuss progress in implementation of the agreements reached in the dialogue, in particular in the run-up to the municipal elections on November 3."
The EU's envoy to Kosovo, Samuel Zbogar, told the Voice of America's Serbian service that a ban on Serbian officials visiting would be "too much", given that all sides wanted to see strong Serb turnout in the local election.
"I think we need to lower tensions and think about it and find a solution," he said, speaking in Serbian.
(Additional reporting by Fatos Bytyci in Pristina and Adrian Croft in Brussels; Editing by Paul Taylor; Writing by Matt Robinson; Editing by Paul Taylor)