Public health experts say the United States’ departure could cripple the WHO’s operations or leave an opening for China to assume greater control over the agency.

Ooh, that’s a big one,” Donald Trump said Monday as he signed an executive order – one of dozens during his first hours as president – to withdraw the United States from the World Health Organization.

The United States has plans to withdraw from the World Health Organization (WHO), the agency announced Tuesday, right after President Donald Trump signed an executive order formalizing the decision.