Kosovo has postponed plans to fine drivers refusing to give up old car licence plates issued by Serbia for another 48 hours, after a United States request for a delay to a move Washington and the European Union fears may trigger ethnic violence.

The dispute over licence plates has stoked tensions for almost two years between Serbia and its former breakaway province, which declared independence in 2008 and is home to a Serb minority in the north that is backed by Belgrade.

Around 50,000 ethnic Serbs who live there refuse to recognise Pristina’s authority, and still consider themselves a part of Serbia. Belgrade has said it will never recognise the independence of Kosovo.

Hundreds of police officers, judges, prosecutors and other state workers from the Serb minority quit their jobs earlier this month Pristina ruled that local Serbs must finally replace car plates issued by Kosovo Serb municipal authorities, loyal to Belgrade, with Kosovo state ones.

Kosovo Prime Minister Albin Kurti signalled the delay in a post on his Twitter account in the early hours of Tuesday. “I accept his (the American ambassador’s) request for a 48-hour postponement … I am happy to work with the U.S. and the EU to find a solution during the next two days.”

Kosovo police had said earlier that fines were supposed to be issued from 08:00 local time (0700 GMT) on Tuesday, and would affect around 10,000 drivers.

Pristina and Belgrade failed to reach a deal on Monday after emergency talks mediated by the EU were held, with Brussels warning of an “escalation of violence” if the plan was to go ahead.

EU foreign policy chief Josep Borrell, who chaired the talks, blamed mainly Kosovo for rejecting an EU proposal on how to resolve the car plates dispute.

Opposition in Pristina has also blamed Kurti of jeopardising relations with the United States as Kosovo’s biggest ally.

Kurti has said he is more interested in reaching a final accord with Serbia where both countries will recognise each other as independent state.

Serbia’s President Aleksandar Vucic said late on Monday that his country would stop issuing and renewing car number plates for the northern part of Kosovo, but warned of growing tensions.

“We received the latest intelligence a little while ago, the situation is very difficult and it is on the verge of conflict,” Vucic told reporters.

NATO, which has around 3,700 peacekeepers on the ground in Kosovo, said it is ready to intervene should the security situation be threatened.