More than 6,000 positive cases of COVID-19 were recorded in California on Monday
anthony fauci
Dr. Anthony Fauci
| Credit: Shutterstock

As counties across the United States continue to reopen their economies, the nation's top health expert says that the coinciding rise in positive cases of the novel coronavirus (COVID-19) in some states is a "disturbing surge."

"The next couple of weeks are going to be critical in our ability to address those surges we are seeing in Florida, Texas, Arizona, and other states," Dr. Anthony Fauci said Tuesday, addressing the House Energy and Commerce Committee, The New York Times reported.

"The virus is not going to disappear," he reportedly added.

California is among the states experiencing a sharp rise in positive COVID-19 cases.

On Monday, more than 6,000 cases of the contagious respiratory virus were recorded, breaking the state's single-day record, according to data collected by the Los Angeles Times. In L.A. County, more than 2,000 positive cases were reported on three different days within the span of a week, the outlet reported.

An increase in testing contributes to the uptick in cases, but L.A. County Public Health Director Barbara Ferrer said that both private and public gatherings are also contributing, the LA Times reported.

Many of the new positive cases have been found in people under 35; in California, that demographic now makes up 44 percent of new infections.

Fauci on Tuesday also opposed Donald Trump's assertion that testing would be decreasing.

"None of us have ever been told to slow down on testing. That just is a fact," Fauci said. "In fact, we will be doing more testing... So it's the opposite. We're going to be doing more testing, not less."

Trump said at his campaign rally in Tulsa, Oklahoma, over the weekend that he had called for a slow-down in testing because more positive cases were a bad look.

"When you do testing to that extent, you're going to find more people, you're going to find more cases. So I said to my people, 'slow the testing down, please.' They test and they test," Trump said.

As information about the coronavirus pandemic rapidly changes, PEOPLE is committed to providing the most recent data in our coverage. Some of the information in this story may have changed after publication. For the latest on COVID-19, readers are encouraged to use online resources from CDC, WHO, and local public health departments. PEOPLE has partnered with GoFundMe to raise money for the COVID-19 Relief Fund, a fundraiser to support everything from frontline responders to families in need, as well as organizations helping communities. For more information or to donate, click here.