evidence: Top US virus researcher Dr Anthony Fauci has called President Donald Trump's sharing of a video which included claims masks are not needed to fight Covid-19 "not helpful". [...] Late on Monday, Mr Trump also retweeted several tweets critical of Dr Fauci. But in Tuesday's briefing the president denied he was criticising the director of the National Institute of Allergy and Infectious Diseases, insisting: "I get along with him very well."