This paper studies how supranational regions are built through the interplay of borders and networks. The focus is on how territory and network become manifest in planning, and in particular on the actual contexts in planning where the territorial discourse is emphasized. Conceptually, territory-network interplay is linked to recent discussions on relational/territorial space, multidimensionality of sociospatial relations, and thin and thick region building. The Barents Euro-Arctic Region is used here as an example, and the region's recent geoeconomic turn is studied first. The paper concludes that, despite geoeconomization, network is not dominant over territory as a key category in supranational region building. Although the contemporary (new) regionalist planning discourse emphasizes the institutionalization of network-oriented regional (economic) spaces without definitive boundaries, processes such as representing the region in branding or (re)deflning who is eligible to join the official structures of cross-border cooperation entail a degree of territorial thinking and make use of the notions of boundedness and spatial symmetry. In planning practices networks commonly create the territory effect and vice versa. However, due to their different ontologies, network and territory can appear as separate or even contradictory discourses as well.