Since the new coronavirus was first detected in Brazil in late February, the virus has spread quickly across the country, with large clusters in São Paulo and Rio de Janeiro, the country’s most populous states. As of Wednesday, there were 6,836 confirmed cases in Brazil, where testing is limited, and 240 recorded deaths.

In a televised address Tuesday night, Mr. Bolsonaro spoke about the virus in graver terms, calling it “the greatest challenge of our generation.”

But the president notably did not endorse strict quarantine measures and misleadingly paraphrased remarks by the head of the World Health Organization to assert that informal workers should continue to toil.

“The collateral effects of the measures to fight the coronavirus cannot be worse than the actual illness,” he said.

In much of the country, his words were drowned out by protesters banging pans and chanting “Down with Bolsonaro!”

In mid-March, governors started urging Brazilians to stay indoors unless they work in critical sectors and called on several business categories to shut down. Since then, commerce, transit and flights have been sharply reduced, throttling Latin America’s largest economy, which has yet to recover from a brutal recession in 2014.

As the patchwork of lockdown measures hardened, Mr. Bolsonaro lashed out at governors for falling into a state of “hysteria” and asserted, without proof, that they were inflating coronavirus figures for political gain. He attacked journalists, accusing them of drumming up panic in an effort to undermine his government. He has called the virus a “measly cold.”