Brazil's President Jair Bolsonaro tested positive for COVID-19 on Tuesday after months of downplaying the virus' severity.

Bolsonaro confirmed the test results while wearing a mask and speaking to reporters in capital Brasilia, and said he is already taking hydroxychloroquine - an anti-malarial drug unproven to effectively treat COVID-19.

"I'm well, normal. I even want to take a walk around here, but I can't due to medical recommendations," Bolsonaro said. "I thought I had it before, given my very dynamic activity. I'm president and on the combat lines. I like to be in the middle of the people."

The 65-year-old populist has often appeared in public to shake hands with supporters and mingle with crowds, at times without a mask. He has said his history as an athlete would protect him from the virus, and it would be nothing more than a "little flu" were he to contract it.

He also repeatedly said there is no way to prevent 70 percent of the population falling ill with COVID-19, and local authorities' measures to shut down economic activity would ultimately cause more hardship than allowing the virus to run its course.

For nearly two months, Brazil's fight against coronavirus has been in the hands of an interim health minister with no health experience before April.

He took over after his predecessor, a doctor and health care consultant, quit in protest over Bolsonaro's support for hydroxychloroquine.

Bolsonaro is "the democratic leader who has most denied the seriousness of this pandemic," said Mauricio Santoro, a political science professor at the State University of Rio de Janeiro.

"Him getting infected is a blow to his credibility. It will be seen as another example of the failure of his coronavirus response," Santoro said.