The EU and US have said Kosovo will not be split in two because of the divide between ethnic groups there.
Mr Feith will act as envoy for 15 countries that recognise Kosovo
"There will be no partition of the country, that is not foreseen," EU special envoy Pieter Feith told a news conference in Vienna.
In Bulgaria, delegations from Kosovo and Serbia met for the first time since independence was declared last Sunday.
Foreign Minister Vuk Jeremic told Balkan foreign ministers that as long as Serbia existed, Kosovo never would.
He said Kosovo would not belong to the world community of sovereign nations and Belgrade would appeal to the International Court of Justice in The Hague over the legitimacy of Kosovo's declaration.
Mr Jeremic appealed to the international community to defer decisions on recognising Kosovo before a ruling was made.
The head of Kosovo's chamber of commerce, Besim Beqaj, attended the gathering under a United Nations banner, the only way Mr Jeremic said he was prepared to accept Kosovo's presence.
Mr Beqaj said that when he spoke, the Serbian delegation did not stay in the room, a statement that could not be confirmed.
No parallel institutions
At the same time, a meeting was held in Vienna of an international steering group comprising 15 nations from those which have recognised Kosovo as an independent state.
Mr Feith, a Dutch diplomat, was named by the group as its international high representative for Kosovo.
Mr Feith admitted that security in Serbian areas of northern Kosovo was difficult but said he was not aware of reports that some Kosovo Serb police officers had not been carrying out their duties.
"We will not admit any parallel security institution to manifest itself on the territory of Kosovo," he said.
He promised what he called "privileged linkages" between ethnic Serbian communities and Belgrade.
That view was backed up by the US state department.
"We absolutely oppose the partition of Kosovo. And the great majority of countries around the world are not going to stand for that," said Under Secretary for Political Affairs Nicholas Burns.