Brazil, which has had more people killed in the pandemic than any country except the United States, also reported 1,185 deaths in the past 24 hours, bringing its total death toll to 53,830.

The jump in infections was the second-highest in a single day in Brazil since the start of the pandemic. However, officials said the record -- 54,771 cases, on June 19 -- was due to system backlogs that had led to under-reporting for previous days.

Brazil now has nearly 1.2 million infections in total.

Experts say under-testing in the country of 212 million people means the real numbers are probably much higher.

The Pan American Health Organization's head of communicable diseases, Marcos Espinal, urged Brazil Wednesday to carry out more tests.

The health ministry later said it would start testing 100 percent of even mild suspected cases in the public health system.

Despite the ongoing surge in infections and deaths, many states in Brazil are pressing ahead with plans to reopen their economies after months of painful stay-at-home measures to contain the virus.

But many experts warn it is too soon.

"We're sending people to the slaughterhouse," said Domingos Alves, a professor of medicine at the University of Sao Paulo and member of a scientific committee monitoring the crisis, COVID-19 Brasil.

"The curve in Brazil is still rising sharply. We're still in the first wave."

Brazil has struggled to set a strategy for dealing with the pandemic.

President Jair Bolsonaro, who has famously compared the virus to a "little flu," has clashed with state and local authorities over their stay-at-home measures.

The far-right leader argues the economic impact of such measures risks being worse than the virus itself.

Lately, however, cities such as Sao Paulo and Rio de Janeiro, the hardest-hit in Brazil, have begun gradually lifting emergency measures, even though the number of infections and deaths is still rising sharply.

Shoppers have swarmed commercial districts in Sao Paulo in recent days, while Rio's famous beaches were packed last weekend, raising concerns about waning adherence to social distancing guidelines.