On Thursday, Borrell held separate meetings with Vucic and Kurti on the sidelines of the EU summit in Brussels to discuss the normalization of relations between the two parties, including the creation of the Community of Serb Municipalities in Kosovo.
"The parties were not ready to agree on that [the establishment of the association] without preconditions, that there were unacceptable by the other party," Borrell said in a statement on Thursday after the meetings.
"At the end, we require the parties to sincerely engage in the normalization process. That can only be done in the framework of the Dialogue, because it is the only way for them to advance on their European path."
The dialogue had previously reached a dead end amid yet another escalation in the region. On June 22, Vucic and Kurti refused to meet in person as part of another round of talks.
In early September, the Serbian leader said that after Kurti came to power in Kosovo in March 2021, 401 attacks against Kosovar Serbs and their property had been reported. Vucic also repeatedly said that he would attend the next round of talks only because it was "the obligation of Belgrade, which advocates a peaceful settlement."
In late May, clashes erupted after Kosovo forcibly installed new ethnic Albanian mayors in offices in several northern cities following municipal elections in April. The polls were boycotted by the Serb community but declared valid despite a less than 3.5% voter turnout. More than 50 Serbian protesters and at least 30 NATO peacekeeping troops were injured in the clashes.