• "For reasons beyond my understanding, we were not able to reach absolutely any agreement," the Serbian President said.

The negotiations with the Kosovo authorities in Brussels on postponing the controversial measures of Pristina were fruitless, Serbian President Aleksandar Vucic said on Monday.

Earlier today, a summit for Belgrade and Pristina was held by EU foreign policy chief Josep Borrell amid the escalation in Kosovo, despite Vucic's pessimism that a deal could be reached. The President and Prime Minister of Kosovo and the EU Special Representative Miroslav Lajcak attended the summit.

"For reasons beyond my understanding, we were not able to reach absolutely any agreement. The Serbian side was completely constructive, and we accepted the amended texts ten times, but the Albanian side did not want to accept anything. All the time they supplemented something impossible, so all I can say is that I want to collect my thoughts, I have saved all the papers [from the meeting] and will appeal to the citizens," Vucic said, as quoted by Serbian state news agency Tanjug.

On Sunday, Vucic did not expect Kosovo to backtrack on its decision to penalize citizens driving with Serbian-issued license plates and warned that the policy may lead the breakaway province to yet another escalation after November 21.

The Kosovo Government require local Serbs to re-register their car plates, demanding that they feature the EU-standard letter code of RKS instead of KM, the Serbian identifier for the disputed region of Kosovska Mitrovica on the border. October 31 was the deadline for the re-registration.

The main reason for the tension is the 2008 declaration of independence of Kosovo which Serbia does not recognize and encourages the Serb minority to remain loyal to Belgrade.

This month, Serbs in northern Kosovo resigned from public institutions in protest over the row on vehicle number plates.

The Serb representatives have since returned to Kosovo's parliament but not to other public bodies.

Pristina has declared that around 10,000 Kosovan Serbs with license plates issued by Serbia must replace them with plates from the Republic of Kosovo by next April, under a gradual plan that would involve warnings, fines, and road bans.

The dispute alarmed the European Union, which has been mediation between the two parties and trying to normalize ties between them.

In August, the EU brokered an agreement to allow free movement between Kosovo and Serbia, after a series of violent incidents.