The Three Seas Initiative harks back as another version of strategic integration in the Central and Eastern Europe. Based on the Neofunctionalism, a functional-based regionalism is expected to take roots in the region with the spillover effect into the political and institutional levels; therefore, the main question of the research study is: what is the effect of the EU on the regionalism in the Central and Eastern Europe? The hypothesis of this research states that the EU’s highly developed institutional arrangement has led to a specific type of regional arrangement to take place in the CEE under the Three Seas Initiative, which lacks highly supranational institutionalism, even though it maintains high functional and political dimensions. The main research question was investigated using the qualitative method, namely descriptive method within the theoretical framework of Neofunctionalism. Results indicate that while Central European regionalism is under the effect of political and functional spillover as well as spill-around in institutionalization, the divide between Central European conservative and Western liberal values has been used by Eurosceptic parties to accelerate the process.
