The World Health Organization (WHO) chief has urged global leaders to pressure the United States to reverse its decision to withdraw from the agency. The US is the WHO's largest donor, contributing an estimated $988 million, or 14% of its budget. The agency warned that the US withdrawal puts critical information about global disease outbreaks at risk and could impact emergency responses and health programs worldwide. WHO officials have asked member countries to lobby on its behalf to convince the US to reconsider its decision.