The fate of the US Agency for International Development (USAID) appeared bleak Monday after Elon Musk, the world’s richest man charged with overhauling the federal government, said President Donald Trump had signed off on shutting the agency down. In Washington, USAID’s headquarters was closed for the day, with employees told in an email to remain at home.

Here’s what to know about the agency:

• USAID was established in 1961 under President John F. Kennedy’s administration and is the US government’s humanitarian arm.

• It dispenses billions of dollars annually across the world in an effort to alleviate poverty, treat diseases, and respond to famines and natural disasters. It also promotes democracy building and development by supporting non-government organizations, independent media and social initiatives.

• USAID is a key soft power tool of the US to foster relations with communities around the world, officials say, noting that US national security is approached with the "three D" pillars: defense, bs2best.at diplomacy and development, led, respectively, by the Defense Department, State Department and USAID.

• Around 60 senior USAID staff were put on leave last week on accusations of attempting to circumvent Trump’s executive order to freeze foreign aid for 90 days. Many more junior staff and contractors within the agency have been placed on furlough as well, multiple sources told CNN.