The commercial launch of 6G communications systems and United Nations Sustainable Development Goals, UN SDGs, are both targeted for 2030. 6G communications is expected to boost global growth and productivity, create new business models and transform many aspects of society. The UN SDGs are a way of framing opportunities and challenges of a desirable future world and cover topics as broad as ending poverty, gender equality, climate change and smart cities. The relationship between these potentially mutually reinforcing forces is currently under-defined. Building on the vision for 6G, a review of megatrends, on-going activities on the relation of mobile communications to the UN SDGs and existing indicators, a novel linkage between 6G and the UN SDGs is proposed via indicators. The white paper has also launched the work of deriving new 6G related indicators to guide the research of 6G systems. The novel linkage is built on the envisaged three-fold role of 6G as a provider of services to help steer and support communities and countries towards reaching the UN SDGs, as an enabler of measuring tool for data collection to help reporting of indicators with hyperlocal granularity, and as a reinforcer of new ecosystems based on 6G technology enablers and 6G network of networks to be developed in line with the UN SDGs that incorporates future mobile communication technologies available in 2030. Related challenges are also identified. An action plan is presented along with prioritized focus areas within the mobile communication sector technology and industry evolution to best support the achievement of the UN SDGs.