German Chancellor Angela Merkel has urged Serbia and Kosovo to reach agreement on joint border controls to help ease tensions in northern Kosovo.

During a brief visit to Pristina Monday for talks with Prime Minister Hashim Thaci, Mrs. Merkel made it clear that Serbia cannot be a candidate for European Union membership until it improves its relations with Kosovo.

She said she also made it clear to Serbian President Boris Tadic, in direct talks earlier this year, what the EU wants. She said an agreement on joint border controls and free trade must be enforced and that Serbia's parallel governmental structures in Kosovo, such as municipalities, courts and schools, must end.

Late last month, Mr. Tadic called on Serbs to abandon roadblocks in the north of Kosovo, saying it is damaging the country's bid for EU membership.

Ethnic Serbs in Kosovo, supported by Belgrade, refuse to recognize Kosovo's 2008 declaration of independence. They have been setting up roadblocks in the border area since July, when Kosovo's ethnic Albanian government tried to take control of the areas under de-facto Serb rule. Chancellor Merkel says the roadblocks also must be removed as part of a solution to the problem.

The ongoing tensions between Belgrade and Kosovo cost Serbia a chance at European Union membership last week. EU leaders delayed any decision on granting Serbia the status of membership candidate until March, citing the dispute.