In 2015, the United Nations (UN) declared 17 Sustainable Development Goals (SDGs) and 169 targets to be achieved by 2030, but the COVID-19 pandemic has stalled the world's progress in pursuing them. This article explores how the pandemic has impacted the public health and education sectors of the world's poorest 46 countries, identified by the UN as "least developed countries" (LDCs). Applying the theoretical lens of international political economy, the author first considers the historical, political and economic causes behind the pre-pandemic underdevelopment of LDCs' public health and education sectors. Next, he examines how the international support mechanisms forged in 2015 for the timely achievement of the SDGs have been affected by the pandemic, especially in the areas of health (SDG 3) and education (SDG 4). Based on a number of purposively selected international and national policy documents as well as a few related texts, the author uses the case of Nepal as an example to demonstrate what has particularly hampered LDCs' sustainable development -- and indeed continues to do so during the ongoing pandemic. He identifies three main adverse factors: (1) the privatisation of health and education; (2) a lack of governmental accountability; and (3) dysfunctional international support mechanisms. The article appeals for a more egalitarian global collaboration and full accountability of LDC governments in the joint effort to achieve a sustainable recovery from the pandemic.