Coronavirus cases reaching record numbers globally are not just the result of more countries testing, the World Health Organization said Monday.
"We do not believe that this is a testing phenomenon," Mike Ryan, executive director of the WHO's emergencies program, said at a news conference at the organization's Geneva headquarters.
"Clearly when you look at the hospital admissions, [they] are also rising in a number of countries and deaths are also rising. They're not due to increased testing per se. So there definitely is a shift in the sense that the virus is now very well established on a global level," he said.
On Sunday, the number of new cases reported to the WHO jumped by more than 183,000, "easily" the most in a single day so far, WHO officials said.
In the U.S., the coronavirus continues to spread throughout parts of the country, now with more than 2.2 million cases as of Monday, according to data compiled by Johns Hopkins University. As of Sunday, the U.S. seven-day average of new Covid-19 cases increased more than 24% compared with a week ago, according to a CNBC analysis of Johns Hopkins data. Cases are growing by 5% or more in 25 states across the U.S., including Arizona, Texas, Florida and Oklahoma. Coronavirus hospitalizations are on the rise as well.
In recent weeks, some state and federal leaders have downplayed the recent rise in cases and hospitalizations across the U.S., tying it to an increase in testing. On Saturday, President Donald Trump said he asked officials to "slow the testing down," reiterating his claims that more testing was the reason the U.S. has the most cases in the world.
Coronavirus "testing is a double-edged sword," Trump said at a rally in Tulsa, Oklahoma. "We have tested 25 million people by now, which is probably 20 million people more than anybody else. Germany has done a lot; South Korea has done a lot. But here's the bad part: when you do testing to that extent, you will find more cases!"
The WHO acknowledged Monday that numbers are also increasing because "the epidemic is developing in a number of populous countries at the same time and across the whole world."
"So from that perspective a large number of countries are contributing to that overall increase," he said.
Meanwhile, Brazil, with nearly 55,000 new infections, saw the largest number of cases reported, followed by the U.S., according to the WHO.
Ryan said there is still a relatively low test per population rate in Brazil and the positivity rate for testing is still quite high.
"I believe the positivity rate was 31% for Brazil, so that generally means that there are probably more cases out there that aren't being reported but what we tend to see is that positivity rate dropping usually down to 5% or less in countries that are detecting all of their cases and they're in effect over-testing," he said.
"So from that perspective we would say that this trend or these large number of cases are not reflective of exhaustive testing but, as I said, probably underestimate the actual number of cases," he said.
WHO Director-General Tedros Adhanom Ghebreyesus said all countries face "a delicate balance between protecting their people while minimizing the social and economic damage."
"It's not a choice between lives and livelihoods. Countries can do both," he said.
-- CNBC's Jasmine Kim contributed to this report.