The international discourse on sustainable development has matured over the past 20 years and taken on myopia of different forms and interpretations. A core requirement of the Rio Agenda is the development of national strategies for sustainable development. While industrialised countries have in many cases undertaken the effort of designing comprehensive strategies to guide sustainable development at the national level, middle-income countries and particularly developing nations struggle even with the process requirements of designing such strategies. This paper aims to shed light on several aspects of the uptake of the sustainable development discourse in middle-income and developing countries. Comparing the situation in South Africa and Kenya, challenges, stumbling blocks as well as favouring conditions for the acceptance of international sustainability discourses into national policy frameworks are identified. Specifically, the analysis assesses the impact of international norms on national policies in the areas of environmental and social protection. Since not only governmental but also non-governmental actors are receptive to the international sustainability discourse, the analysis is augmented by taking into account the contribution and transformative power of other societal actors. The findings demonstrate that non-governmental in fact support transformative processes towards adopting sustainability policies. Similarly conducive are international capacity- building and facilitation efforts. The eventual adoption however depends on the willingness and capacity of national government actors.