Nowadays, the role of international regional economic integration as an association is transforming in today's rapidly changing world. If at the beginning these international associations had a purely economic function, today they should be seen as successful mediators between, for example, the transition to renewable energy sources and sustainable development, or between e-government and sustainable development. The article describes the main theoretical areas that are relevant for assessing the effectiveness of international regional economic integration processes. First, a brief historical digression is made, and then the current state of the issue is analyzed. It is noted that the widespread transition to the use of renewable energy sources and e-government resources is crucial for achieving the sustainable development goals of the United Nations Development Program. The article will be of interest to scientific and educational organizations as well as relevant agencies dealing with the issues of international regional economic integration in the context of sustainable development of various regions of the world.