This publication is a part of the Global Support Programme (GSP; https://www.un-gsp. org/), which supports non-Annex I Parties in preparing their National Communications and Biennial Update Reports that are submitted to the United Nations Framework Convention on Climate Change (UNFCCC). The GSP provides support to the developing countries that includes technical backstopping, tools and targeted guidance, and training to carry out the preparation of these reports. The GSP also assists developing countries in strengthening national institutional arrangements to support the new reporting requirements and ensure alignment with national development priorities. Mitigation of greenhouse gases (GHGs) is an important measure to address climate change. All the Parties (i.e. countries, signatories to the UNFCCC) have agreed to address and cooperate under the framework of UNFCCC. After the Paris Agreement of 2015, the countries submitted their Nationally Determined Contributions (NDCs), which indicate the actions that countries commit to take for mitigation and adaptation. The identified mitigation actions need to be appropriately assessed, and their expected contribution to mitigation reported to UNFCCC. The GSP support for mitigation assessment includes providing guidance on cost-benefit analysis of mitigation options and socio-economic implications, suitable models for national level mitigation analysis, calculations of mitigation potentials and others.