The right-wing populist told a group of television reporters that he had developed symptoms at the weekend.

"It started on Sunday with a certain malaise and became worse throughout the day on Monday, feeling poorly, exhaustion, a bit of muscle ache, fever hit 38 (degrees Celsius)," he said.

Finishing the interview, he stepped back and removed his mask to reveal a smile, adding: "You can see from my face that I'm well and I'm calm."

Bolsonaro said he has been taking hydroxychloroquine, an anti-malarial drug with unproven effectiveness against COVID-19.

Bolsonaro has emulated his political role model Donald Trump in voicing skepticism about the virulence of the virus, although the US president has moderated his tone.

Bolsonaro tested negative in March for the coronavirus after several aides were diagnosed following a visit to Trump's Mar-a-Lago, Florida, resort.

Over the weekend, Bolsonaro was also in close contact with US Ambassador Todd Chapman during July 4 celebrations. Pictures showed neither wearing a mask.

Brazilian financial markets retreated following the news. Brazil's currency, the real, swung into negative territory and the benchmark stock index deepened losses to 1.5 percent.

eNCA