A scientist whose coronavirus projection model is cited by the CDC warned Tuesday that states may have to close again if COVID-19 cases increase.
This comes as some states across the U.S. are easing their lockdown measures and reopening some businesses.
But the coronavirus scientist, Youyang Gu, believes states that rush to reopen could see a spike in cases and by the time they realize it, it could be too late.
He said, "It will be at least two to three weeks before we see an increase in the number of infections because it takes time for individuals to infect others and for them to display symptoms. ...At each stage, there's a lag time."
Gu brought up the Japanese island of Hokkaido, where infections spiked once everything reopened. The government had to put everything on lockdown again after just three weeks.
Some states have already started loosening restrictions despite not meeting recommended guidelines from health experts.
The White House's "Opening Up America Again" guidelines say states shouldn't reopen until they've maintained a downward trajectory of positive cases for at least two weeks.
But some are eager for things to reopen in states that still have stay-at-home orders, with some people rallying to urge government officials to ease the lockdowns.
President Trump said the projected number of coronavirus deaths in the U.S. could reach 100,000 but insisted the country should reopen soon saying, "We can have it both ways and reopen."
Contains footage from CNN.