AbstractDuring negotiations in the initial stage of multinational megaprojects, technical issues are underemphasized compared to diplomatic or political perspectives despite varying relevant standards of participating countries. If the organization structures are established soundly while overcoming heterogeneous aspects of involved countries, decision making among countries satisfying both could be made timely and properly. With the aim of positive multilateral relationships and negotiations concerning engineering factors collectively, a framework is presented for identifying the roles and responsibilities of multinational joint clients with a hierarchical organization structure composed of a decision maker, senior responsible owner, project sponsor, and project manager. US forces relocation program in the Republic of Korea, a $1.4 billion megaproject, was analyzed where political and cultural aspects were attempted to melt down in a hierarchical organization. Results from interviewing high-level decision makers from both countries show that upper-level participants focus on political issues, while lower-level practitioners aim to achieve satisfactory technical quality. The involvement of engineers in earlier negotiation stages with upper-level counterparts is essential in establishing realistic goals. The uniqueness of the framework compared to previous factor-driven perspectives between different joint-client structures are as follows: Identical hierarchy of level from the countries supports defining roles with integrated scope management, and neutral consultative body for arbitrating conflict between countries and in-house departments within a country is required.