Many parts of the country are "just at the beginning" of the coronavirus outbreak, said a former director of the Centers for Disease Control and Prevention on Sunday, while agreeing with the current CDC director's assessment that the death toll here from the virus could hit 100,000 in just weeks.

"Tragically, this is a really bad virus, and we are just at the beginning. We’re in different places in different parts of the country. In New York City, where I am today and where I live, we are at the end of the beginning. In some other places of the country, it hasn't yet hit in full force," Dr. Tom Frieden, the former CDC director, told "Fox News Sunday," according to a transcript. 

That grim outlook came just days after current CDC director, Dr. Robert Redfield, said over Twitter that based on forecasting models, "we will see deaths exceeding 100,000 by June 1."

It also comes a week after a top disease expert, Michael Osterholm, at the University of Minnesota, said that up to 70% of the nation could get infected with the potentially fatal disease Covid-19, which is caused by the virus that originated in China late last year.

"I think you may well hit that in the U.S.," Dr. David N. Fisman, a professor of epidemiology at the University of Toronto, told TheStreet by email. "Time will tell, but the rush to reopen businesses and suspend distancing in many states is likely to restart exponential epidemic growth. You can keep that down with a stronger and more coordinated response to disease control."

Dr. Fisman used the dramatic rise in cases in Texas over the weekend as an example, and called proposals for a grand reopening of the nation amid the pandemic "foolhardy."

Much of the nation -- including President Donald Trump -- have expressed growing interest in reopening the economy as the number of people out of a job because of shutdowns and stay-at-home policies have grown to the tens of millions and is rapidly rising weekly, and retailers are especially getting hit hard, with sales plunging 16.4% in April.

As of Sunday morning, the U.S. was on track to hit 1.5 million total known cases of Covid-19. The U.S. was also quickly approaching 90,000 deaths -- a number that surpasses the total number of cases reported in all of China, according to the Johns Hopkins map of the outbreak

Better data and global surveillance is needed to inform reopenings and responses to the spread of the virus, wrote a team of doctors and scientists in the Journal of American Medical Association on Sunday.

"There is an urgent need for Covid-19 data, including community-level incidence, spectrum of disease, diagnostic test penetration, and proportion of the community with protective immunity," wrote the group in JAMA. "Real-time incidence and seroepidemiologic data are also essential to plan scenarios for the development of Covid-19 vaccines and therapeutics. Cross-sectional community surveys combined with seroepidemiology can help inform the present and help navigate the path forward."

But also on Sunday, a top Trump official said that continuing to lock down the nation could be deadlier than the virus itself.

Peter Navarro, who has no medical background but is a trade adviser to the president, said, "going forward with these guidelines, the important thing to understand here for the American people is this: opening up this economy is not a question of lives vs. jobs. The fact of the matter is, and what President Trump realized early on, is that if you lock people down you may save lives directly from the China virus. But you indirectly, you're going to kill a lot more people."

Navarro was speaking to NBC News host Chuck Todd on "Meet the Press."

Navarro went on to claim to Todd that "statistically based on our experience with the China trade shock in the 2000s" that unemployment could lead to an uptick in suicides, depression and drug abuse. He added that during the lockdowns, "women haven't been getting mammograms or cervical examinations for cancer. We haven't been able to do other procedures for the heart or the kidneys. And that's going to kill people as well. So, if you contrast like this complete lockdown where some of the people in the medical community want to just run and hide until the virus is extinguished, that's going to not only take a huge toll on the American economy, it's going to kill many more people than virus, the China virus ever would."

Fed Chairman Jerome Powell warned, however, that the nation should not expect a full recovery until a vaccine is available. 

Assuming there is not a second wave of the coronavirus, I think you will see the economy recover steadily through the second half of this year," Powell said in remarks broadcast on CBS's "Face the Nation." "For the economy to fully recover people will have to be fully confident and that may have to await the arrival of a vaccine.”

And Dr. Frieden cautioned on Fox that trying to go back life as usual could have deadly consequences.

"We’re all tired of waiting at home. We want to get out. I want to get back to the gym. We want to get back to our lives. We want to get our economy back. 

But at the same time, if we go too fast, it will backfire and we can see explosive spread that could bring us back in.... The virus is the enemy here."