The external border of the EU and NATO is overlapping the state border between Romania and Ukraine, for a length of 440.1 km in a dominating mountain range of the Carpathians Mountains. By applying specific methods and tools we have identified in quantitative, qualitative and functional-systemic terms, the factors that determine and the items that compose the functioning mechanisms of the Romanian and Ukrainian border contiguous areas. There were considered: the geographical location; the natural morpho-structural aspects; the morphological support profile of the state border; the legislative and administrative framework; the routes and communication networks; the historical, social and cultural elements etc. Based on the results obtained, new strategies can be generated for transforming these areas into a cross-border territorial system with high degree of functionality. Such a system has an important role in the process of social and economic integration and elimination of the traditional functions of the political frontier generating juxtaposed territorial systems