US President Donald Trump has accused the "deep state" in the Food and Drug Administration (FDA) of trying to slow down the search for a vaccine until after the November election.
He suggested on Twitter - without any evidence - that "they are hoping to delay" finding a successful drug for Covid-19 by working to slow testing of vaccines and treatments.
Mr Trump said the deep state "or whoever" at the FDA was making it "very difficult" for drug companies to enroll people in clinical trials to test vaccines and therapies for coronavirus.
He addressed his tweet to FDA commissioner Dr Stephen Hahn. The accusation came after Reuters reported on Thursday that a top FDA official said he would resign if the Trump administration approved a vaccine