Countries worldwide are facing complex and diverse health challenges in 21st century, and usually there is one national health system for individual and population health outcomes. The COVID-19 pandemic and other emerging health challenges have exposed gaps and fragmentation in health systems with limited public health capacities and governance. In this context, “essential public health functions” (EPHFs) have been revitalized to support an integrated approach to sustainable health systems strengthening, complementary to primary health care, various programme-specific and health security approaches. Resolution WHA69.1 identified “public health functions as the most cost-effective, comprehensive and sustainable way to enhance the health of populations and individuals and to reduce the burden of disease”; operational framework for primary health care highlighted EPHFs as a key consideration to provide public health services; and WHO’s position paper on building health systems resilience towards universal health coverage (UHC) and health security recommended investing in EPHFs as a key mean for countries’ health systems recovery and transformation during COVID-19 and beyond.