Ivanovic rose to prominence after the Kosovo war in 1999, which ended with Serbian forces pulling out of the mostly Albanian-populated region.
"Unfortunately, I wish it weren't true, but doctors declared Oliver dead at 9.30 this morning", Nebojsa Vlajic said.
Ivanovic, 64, was fatally injured by an unidentified assailant in front of the office of his Citizens' Initiative Party, Serbian state television reported.
Tensions between Kosovo's Albanian majority and Serb minority are becoming increasingly strained, especially in the divided town of Mitrovica, where Ivanovic lived.
A Kosovo court convicted Ivanović of war crimes during the 1998-99 war. It declared independence from Belgrade in 2008, and though the country is not a member of the United Nations, it's recognized as an independent country by more than 100 countries - including the United States, Britain and Germany.
Marko Djuric, the head of the Serbian Government's Office for Kosovo and Metohija, said its delegation was "returning to Belgrade immediately".
In Pristina, the Kosovo government strongly denounced the slaying, saying it considered the attack a challenge to "efforts to establish the rule of law in the whole of Kosovo territory".
Airbus says A380 superjumbo production could end
Boeing released its 2017 deliveries and orders figures last week . The airframer delivered 15 of the type over the course of 2017.
Brian Daboll leaving Alabama to be Buffalo Bills offensive coordinator
Back then, Daboll was on the coaching staff while McDermott was in his senior season with the Tribe. Less than a week after winning a national championship at Alabama, Brain Daboll has a new job.
Spec 2019 Ford Ranger unveiled, gets 2.3T with 10-spd auto
Altogether the Ford Ranger should be received very well and will make an impact on the already competitive mid-size truck market. In addition, the engine features a forged-steel crankshaft and connecting rods, and chain-driven dual overhead cams.
In February previous year, a Pristina appeals court quashed the sentence and ordered a retrial for Ivanovic, who had been in detention since his arrest in January 2014 until the acquittal. "We can't rule out that someone had been planning this for a long time, and wanted to delay the process of the normalization of relations, now being held in Brussels, as well as postpone the creation of a Serbian municipalities association in Kosovo".
Juric reminded that in recent days Serbian activists in Kosovo have been receiving threats from various political unions of local Albanians.
The Serb and Kosovar delegations had come to Brussels on Tuesday at the level of chief negotiators on both sides to talk about the ASM, among other issues.
In the wake of the murder, Belgrade broke off EU-sponsored talks with Kosovo.
In 2016 he was found guilty of war crimes linked to the killings of four ethnic Albanians during the war and was jailed for nine years.
North Atlantic Treaty Organisation air strikes on Serbia forced Belgrade to withdraw troops from Kosovo in 1999 and the US-led alliance keeps 5,000 soldiers there to maintain a delicate peace. Serbia does not recognize the split and EU-mediated talks have been underway in a bid to normalize ties.