The White House doctor said Trump did not need to be tested or quarantined despite sitting at a banquet table with Brazilian officials infected with nCoV last week.

"These contacts are classified as 'low risk' according to the steps of the Centers for Disease Control and Prevention (CDC), so President Donald Trump does not need home isolation at this time. The system also has no symptoms, so it is not necessary to appoint a nCoV test, "said the White House doctor on March 13.

Doubts about nCoV testing with Trump arose after three Brazilian delegation members who had close contact with him were infected with nCov. One of them sat at a table with Trump at the Mar-a-Lago resort, Florida, on March 7. Trump shook hands, taking pictures with other nCoV-infected Brazilian officials.

White House press secretary Stephanie Grisham said on March 12 that Trump and Vice President Mike Pence "had not been ordered to test for nCoV". At a press conference the next day, Trump said he could "get tested soon".

A senior official said the White House was constantly evaluating Trump's ability to test for nCoV, and put measures to prevent infection among the US president's close friends.

Some of Trump's close politicians, such as Senators Lindsey Graham and Rick Scott, Senators Matt Gaetz and Doug Collins and White House Chief of Staff Mark Meadows, have quarantined themselves after interacting with people infected with nCoV.

Covid-19 has appeared in 48 states and Washington D.C. In the US, more than 2,300 people were infected, of which 50 died. The worst affected state is Washington with over 500 cases and more than 30 deaths.

Covid-19 in 145 countries and territories with more than 145,000 cases, more than 5,400 deaths and more than 72,000 have recovered. The number of new nCoV infections in recent days has tended to decrease in China and South Korea, but increased in Italy, Iran, Spain, France, Germany and the US.