A U.S. State Department official has called for an end to Kosovo’s taxes on Serbian goods so that European Union-mediated talks on resolving the dispute between the former war foes could resume.

Deputy Assistant Secretary of State Matthew Palmer said Monday full normalization of relations between Serbia and its former province is “essential” for the future of Western Balkans.

Kosovo declared independence in 2008 which Serbia does not recognize. The EU-mediated dialogue has stalled after Kosovo introduced a 100% tariff on all goods coming from Serbia and Bosnia last year.

Palmer said the tariffs present an “obstacle” for the dialogue and should be “lifted or suspended in such a way that would allow for the parties to return to the negotiating table.”