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.

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.

President Donald Trump announced Monday he is withdrawing the US from the World Health Organization, a significant move on his first day back in the White House cutting ties with the United Nations’ public health agency and drawing criticism from public health experts.