Methodical planning for formulating sustainability policy is needed to meet the ambitious United Nations Sustainable Development Goals (SDGs). This paper proposes an approach for such planning for low-income nations by systematically dividing the principal sustainability policy into manageable policy categories. These categories encompass all 17 SDGs, enabling policymakers to take into account the complex interlinkages of the SDGs for sustainability planning. Key actions that need to be taken in each policy category to enhance sustainability are then identified. In order to ensure that the planning process is holistic, analysis of the interlinkages of SDGs is carried out based on prioritisation of the relative importance of each Goal. Although the priority of each Goal can be country specific, interlinkages among Goals 1, 7 and 9 are analysed as an example to illustrate the proposed approach. Top-down approach of the UN's global sustainability agenda is integrated with a bottom-up approach of empowering and promoting local knowledge of low-income nations to develop the planning and policy approach presented in this paper. Finally, research gaps are highlighted to support the achievement of sustainability targets and further enhance the benefits of academic research to low-income nations.