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.

One of President Trump’s first executive orders removes the U.S. from the global health organization, which experts say is “cataclysmic.”

President Donald Trump is pulling the U.S. out of the World Health Organization, raising concerns about the U.N. agency's ability to fight diseases and respond to emergencies around the globe without its biggest funder.