WHO is the directing and coordinating authority on international health within the United Nations' system. It provides leadership on matters critical to health and engages in partnerships where joint action is needed. It shapes the research agenda and stimulates the generation, translation and dissemination of valuable knowledge. WHO also sets norms and standards, promotes and monitors their implementation. It articulates ethical and evidence-based policy options for public health, support its 194 Member States, catalysing change, and building sustainable institutional capacity at country level. WHO also monitors the health situation and assessing health trends.