Staffers of the U.S. Agency for International Development were instructed to stay out of the agency’s Washington headquarters on Monday, according to a notice distributed to them, after billionaire Elon Musk announced President Donald Trump had agreed with him to shut the agency.

Elon Musk called USAID a criminal organization that should “die.” Proponents say it’s a key arm of U.S. influence that, if destroyed, “cannot be easily rebuilt.”