The number of coronavirus cases detected in the United States rose past half a million over the Easter weekend with 18,700 deaths, as President Donald Trump said the decision on when it was safe to reopen the country would be the biggest he had ever had to make.

Public health experts have warned that the US death toll could spike to 200,000 over the summer if unprecedented stay-at-home orders that have closed businesses and kept most Americans indoors are lifted after 30 days.