The complex and global nature of transboundary environmental challenges, from climate change to biodiversity loss, shows that governments alone cannot ensure environmental protection. The multilevel governance model can be considered as a superior political alternative to provide policy solutions to challenges that are located at different territorial levels and therefore require the participation of different levels of governance. By emphasizing the interaction of different levels (local, national, regional and international) and the role of non-state actors, multilevel governance offers a new analytical framework for understanding and implementing the international responsibility of states. This article uses a descriptive-analytical approach to address the issue of how the multilevel governance model has transformed the international responsibility of states for violating environmental obligations. The findings show that this model has shifted government responsibility from a hierarchical and centralized concept to a network of shared but distinct responsibilities, based on the principle of cooperation and collective action, and has created new mechanisms for accountability and redress.