A White House spokesman said Trump did not need to test for nCoV despite having met a Brazilian official who was positive for the virus.

"The White House learned that a member of the Brazilian delegation found positive on the Covid-19 test," spokesman Stephanie Grisham said in a statement on March 12. "President Trump and Vice President Mike Pence have almost no interaction with this individual. They don't need to be tested at the moment."

Earlier on the same day, Brazilian media reported that Fabio Wajngarten, who accompanied President Jair Bolsonaro during a visit to Florida, US, last weekend, was positive for nCoV. Wajngarten, Bolsonaro's press secretary, will take the second sample of the nCoV test for final confirmation, O Estado de S. Paulo said but did not disclose the source.

Photos on social media show Wajngarten standing next to the US President, wearing a hat with the slogan "Make America Great again" at Trump's Mar-a-Lago resort in Florida.

Asked about the WCongarten infection with nCoV, President Trump said he was "not worried".

"We didn't do anything unusual. We sat side by side for a while," Trump told reporters at the White House.

Grisham said that according to government guidelines, those who do not show signs of illness do not need to be tested and only those who have been in close contact for a long time with positive cases should quarantine themselves.

Brazilian President Bolsonaro, 64, yesterday canceled the agenda and is under medical surveillance at his residence. He said the sample was taken and "results will be available in a few hours".

"I'm using a mask because when I came home after my recent visit to the United States, one of our escorts was tested in Sao Paulo and positive," Bolsonaro said on Facebook.

Earlier, the Brazilian leader had mitigated the severity of Covid-19, saying that the epidemic had been "exaggerated".

The US currently records 1,670 cases of nCoV, of which 40 are fatal. Brazil has recorded 52 cases and no deaths have been reported.