The beginnings of formal cooperation can be traced to the Bosnian War; Republika Srpska got support from Serbia. At the Dayton Agreement, the President of the Federal Republic of YugoslaviaSlobodan Milošević represented the Bosnian Serb interests due to absence of Radovan Karadžić. Dayton Agreement ensure the right for entities in Bosnia and Herzegovina to establish special parallel relationships with neighboring countries consistent with sovereignty and territorial integrity of Bosnia and Herzegovina. Agreement on Special Parallel Relations is signed in February 28, 1997. Until now was organized significant number of formal and informal meetings between representatives of two sides.
Republika Srpska supports position of Serbia in dispute over Kosovo. On 21 February 2008 Republika Srpska adopted resolution through which it denounced and refused to recognise the declaration of independence of Kosovo from Serbia. In addition, the parliament adopted resolution stating that in the event that majority of EU and UN states recognise Kosovo's independence, Republika Srpska would cite the Kosovo secession as a precedent and move to hold a referendum on its own constitutional status within Bosnia and Herzegovina. Finally, the resolution called upon all Republika Srpska officials to do everything in order to prevent Bosnia and Herzegovina from recognising Kosovo's declared independence. Regardless of Declaration part that calls for referendum in Republika Srpska, Serbia's official position remained unchanged and continued to support the sovereignty and integrity of Bosnia and Herzegovina.