A restaurant with takeaway service is seen in Arlington, Virginia, the United States, April 4, 2020. The number of COVID-19 cases in the United States topped 300,000 by 3:40 p.m. local time Saturday (1940 GMT), according to the Center for Systems Science and Engineering (CSSE) at Johns Hopkins University. (Xinhua/Liu Jie)

Shoppers with masks line up outside a supermarket in Arlington, Virginia, the United States, April 4, 2020. The number of COVID-19 cases in the United States topped 300,000 by 3:40 p.m. local time Saturday (1940 GMT), according to the Center for Systems Science and Engineering (CSSE) at Johns Hopkins University. (Xinhua/Liu Jie)

A shopper (R) wearing a mask buys vegetables in a supermarket in Falls Church, Virginia, the United States, April 4, 2020. The number of COVID-19 cases in the United States topped 300,000 by 3:40 p.m. local time Saturday (1940 GMT), according to the Center for Systems Science and Engineering (CSSE) at Johns Hopkins University. (Xinhua/Liu Jie)

A shopper (L) wearing a mask walks into a supermarket in Arlington, Virginia, the United States, April 4, 2020. The number of COVID-19 cases in the United States topped 300,000 by 3:40 p.m. local time Saturday (1940 GMT), according to the Center for Systems Science and Engineering (CSSE) at Johns Hopkins University. (Xinhua/Liu Jie)

Shoppers with scarves and masks line up outside a supermarket in Arlington, Virginia, the United States, April 4, 2020. The number of COVID-19 cases in the United States topped 300,000 by 3:40 p.m. local time Saturday (1940 GMT), according to the Center for Systems Science and Engineering (CSSE) at Johns Hopkins University. (Xinhua/Liu Jie)

A restaurant with takeaway service is seen in Arlington, Virginia, the United States, April 4, 2020. The number of COVID-19 cases in the United States topped 300,000 by 3:40 p.m. local time Saturday (1940 GMT), according to the Center for Systems Science and Engineering (CSSE) at Johns Hopkins University. (Xinhua/Liu Jie)

A man wearing a scarf walks on the street in Arlington, Virginia, the United States, April 4, 2020. The number of COVID-19 cases in the United States topped 300,000 by 3:40 p.m. local time Saturday (1940 GMT), according to the Center for Systems Science and Engineering (CSSE) at Johns Hopkins University. (Xinhua/Liu Jie)