"I did the test now. Early tomorrow the results will come out," Bolsonaro told supporters, speaking at a distance across the moat in front of his official residence.

"If God wants to give a negative, things will return to normal."

Outside of the United States, Brazil is the worst-hit country in the coronavirus pandemic. The presidents of both countries have played down the extent of the crisis.

Bolsonaro is one of nearly 2.2 million people in Brazil who have tested positive for the novel coronavirus, according to health ministry statistics released on Tuesday.

More than 81,000 people have died from COVID-19 in Brazil.

Bolsonaro tested positive for the novel coronavirus on July 7 but by the next day said he was already feeling well. A follow-up test last week also came back positive for the virus.

Bolsonaro has previously said he has taken the anti-malarial drug hydroxycloroquine - unproven for treating coronavirus but touted by US President Donald Trump - and credits the medication as the reason for his mild symptoms.

He said that he will travel to the northeastern state of Piaui on Friday, presuming he is well.

With the toll of the pandemic rising rapidly, Brazil is also a major center for testing potential vaccines for the virus. On Tuesday, human trials of a second vaccine began and the government approved trials of a third.