BRUSSELS (AP) -- Serbia and Kosovo reached a potentially historic agreement Friday to normalize relations between the Balkan neighbors, end years of acrimony and put them both on a solid path to European Union membership.
The tentative deal culminated months of tense negotiations and showed determination of both Serbian Prime Minister Ivica Dacic and Kosovo Prime Minister Hashim Thaci, EU negotiator Catherine Ashton said.
"What we are seeing is a step away from the past and for both of them a step closer to Europe," Ashton, the EU's foreign policy chief, said.
In what would be an extraordinary change, the deal appeared to recognize the authority of the Kosovo government over the north of the country, which is inhabited predominantly by ethnic Serbs.
But Dacic appeared to indicate there was a chance the deal could still come unstuck, saying Serbia's top leadership would decide whether to accept or reject the tentative agreement "in the next few days."
Details of the agreement were scant, but Dacic said it was "better than any other we were offered in the past."
Kosovo, a former province of Serbia, declared independence in 2008. Over the years, Belgrade has said it would never recognize the sovereignty of Kosovo, which is considered by Serbia's nationalists to be the cradle of the country's medieval statehood and religion.
Kosovo has been recognized by more than 90 countries including the U.S. and 22 of the EU's 27 members. Because of a blockade by Serbian allies Russia and China in the Security Council, Kosovo is not a U.N. member.
But U.N. Secretary-General Ban Ki-moon welcomed "the landmark agreement between Belgrade and Pristina," according to a statement from his office.
"He strongly encourages the parties to conclude this historic process and take concrete measures for a faithful implementation of the agreement," the statement added. "The United Nations stands ready to assist the parties in this endeavor."
Serbia relinquished control of most of Kosovo in 1999 when NATO chased its troops out of the region after a three-month bombing campaign. Ending the partition of Kosovo between the Albanian majority and the Serb-controlled north -- about a fifth of the country -- is a key condition of Serbia's further progress toward EU membership.
The status of northern Kosovo, which is inhabited primarily by ethnic Serbs who do not recognize Kosovo's predominantly ethnic Albanian government, has been among the thorniest issues of the talks.
Northern Kosovo Serb hardline leaders rejected the tentative deal, saying they will refuse to implement it. They also announced the formation of their own "assembly" -- a move tantamount to proclaiming independence from the rest of Kosovo.
"We stand by our agreement not to allow the implementation of the agreement," Kosovo Serb leader Krstimir Pantic said.
Thaci said reaching an agreement had been difficult, and there were people in both countries who wouldn't be happy with it. But he said it represented a new era.
"This agreement will help us heal the wounds of the past if we have the wisdom and the knowledge to implement it in practice," he said.
In Kosovo, some ethnic Albanians cast doubt on the deal.
"This animosity has existed for a very long time. We fooled ourselves that it wasn't there even in (Yugoslav leader) Tito's times as if we loved one another," Emin Rexhepi, a 38-year-old resident of Pristina, said.
"I wish there was some result and that we could all at least live with one another as one should."
But Kosovo's minister for European integration, Vlora Citaku, was hopeful the announcement could be the beginning of a new era for the Balkan countries.
Citaku, an influential figure in Thaci's party, tweeted: "And the white smoke is out! Habemus pactum! Happy."
German Foreign Minister Guido Westerwelle hailed what he called a "historic step on the way to good neighborliness and a European future."
"Both sides have shown courage and farsightedness," Westerwelle said in a statement, in which he went out of his way to praise Ashton for her mediation and said she "achieved a great success for EU diplomacy."
Thaci said the deal would pave the way for both Kosovo and Serbia to ultimately joint the European Union, and for Kosovo to pursuit its aspiration to join NATO. A precondition for joining the EU is that countries "normalize" relations with their neighbors.
It appeared that the deal meant that the Kosovo Serbs were being told by the Serbian government in Belgrade to live in Kosovo, under the authority of the ethnic Albanian government in Pristina -- and not in Serbia, of which they claim to be a part.