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 U.S. has traditionally been the most generous benefactor of the WHO. A Trump executive order to cut ties with the WHO could pose a threat to global public health.

The United States will exit the World Health Organization, President Donald Trump said on Monday, saying the global health agency had mishandled the COVID-19 pandemic and other international health crises.