Dr. Scott Gottlieb told on Friday he believes the coronavirus is significantly more widespread in the U.S. than official case counts reflect as the highly contagious delta variant sweeps the nation.

“I wouldn’t be surprised if, on the whole, we’re infecting up to a million people a day right now, and we’re just picking up maybe a 10th of that or less than a 10th of that,” the former Food and Drug Administration commissioner said in an interview on “Squawk Box.” Gottlieb now serves on the board of Covid vaccine maker Pfizer.

The current seven-day average of new daily coronavirus cases in the U.S. is roughly 67,000, according to a CNBC analysis of Johns Hopkins University data. That’s up 53% compared with a week ago, as the country grapples with a surge in new infections driven largely by delta, first discovered in India and now the dominant variant in the U.S.

The highest seven-day day average of new Covid cases recorded in the U.S. was roughly 251,000 on Jan. 8, according to analysis. Case counts had dropped off dramatically in the spring as the country’s vaccination campaign picked up speed.

But in recent weeks, as U.S. cases again started to accelerate, Gottlieb has said a large number of coronavirus infections were likely going unreported because the testing landscape is different now than at earlier stages in the pandemic.

For example, he previously told CNBC people can now complete at-home tests and those results are unlikely to make their way to health authorities and then show up in official case counts.

Additionally, Gottlieb has said vaccinated Americans who may become infected are likely to have a mild case or remain entirely asymptomatic, making them less likely to seek out a Covid test than they would’ve been before they were inoculated against the disease.