Photo taken on March 20, 2020 shows a Mexican restaurant closed due to COVID-19 epidemic in New Orleans, Louisiana, the United States. The number of COVID-19 cases in the United States topped 20,000 as of 1:30 p.m. local time on Saturday (1730 GMT), according to the Center for Systems Science and Engineering (CSSE) at Johns Hopkins University. (Photos: Xinhua)

Photo taken on March 20, 2020 shows a library closed due to COVID-19 epidemic in New Orleans, Louisiana, the United States. The number of COVID-19 cases in the United States topped 20,000 as of 1:30 p.m. local time on Saturday (1730 GMT), according to the Center for Systems Science and Engineering (CSSE) at Johns Hopkins University.

Photo taken on March 20, 2020 shows a sign saying "Open for take out" at a restaurant in New Orleans, Louisiana, the United States. The number of COVID-19 cases in the United States topped 20,000 as of 1:30 p.m. local time on Saturday (1730 GMT), according to the Center for Systems Science and Engineering (CSSE) at Johns Hopkins University.