RIO DE JANEIRO, BRAZIL – The science has never been better, but political will has reached a new low: AIDS experts warned Monday that the fight against HIV was in real danger as funding fell by a fifth last year.

A major international AIDS conference got underway in Rio de Janeiro for the first time since the United States began to dramatically slash foreign aid following Donald Trump’s return to the White House last year.

European nations including France, Germany and the U.K. followed suit.