W.H.O. history. It is nominally under the UN but has its own Constitution

Its budget was $5 million in 1948. Current budget a bit under $4 billion. Desired budget $60 billion/year to manage the world whenever it declares a pandemic.

Biden restored the US contribution to WHO and gave more than ever before, most in voluntary contributions, some of which may have had something to do with WHO going along with USG plans for the pandemic treaty and IHR amendments.

https://www.thelancet.com/pdfs/journals/lancet/PIIS0140-6736(02)11244-X.pdf