The World Health Organization is shaped by its members: 194 countries that set health priorities and make agreements about how to share critical data, treatments, and vaccines during international emergencies.

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.

Public health experts say U.S. withdrawal from the W.H.O. would undermine the nation’s standing as a global health leader and make it harder to fight the next pandemic.

This afternoon, the Associated Press is reporting that United States officials have officially ordered all public health officers to cease working at the World Health Organization just days after President Donald Trump signed an executive order pulling the United States out of the World Health Organization.

The WHO is an agency of the United Nations tasked with coordinating responses to public health emergencies between nations. The United States is a founding member of the organization, which was set up in 1948 in the wake of World War II.

The United States will leave 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.

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.

WHO’s constitution, drafted in New York, doesn’t have a clear exit method for member states. A joint resolution by Congress in 1948 outlined that the U.S. can withdraw with one year's notice. This is contingent, however, on ensuring that its financial obligations to WHO “shall be met in full for the organization’s current fiscal year.”

The ending of the commitment to the World Health Organization by the United States poses as an existential threat to the well-being of the international working class.

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.