WASHINGTON — Dr. Anthony Fauci suggested Thursday night that all Americans should be under a stay-at-home order to mitigate the spread of the coronavirus, and that all states should be operating under the same guidelines.

“I don't understand why that's not happening,” Fauci, a member of the White House coronavirus task force and director of the National Institute of Allergy and Infectious Diseases, said in an interview on CNN.

There has been no federally mandated order for everyone to follow the same guidelines, and Fauci appeared to stop short of endorsing one by the Trump administration.

“The tension between federally mandated versus states rights to do what they want is something I don't want to get into, but if you look at what's going on in this country I just don't understand why we're not doing that — we really should be,” he said.

As of Friday, 39 states and Washington, D.C., were under stay-at-home orders while 11 states have not issued statewide orders. There are orders in regions of several states: Alabama, Missouri, Oklahoma, South Carolina, Utah and Wyoming. And there are no orders at all in Arkansas, Iowa, Nebraska, North Dakota and South Dakota.

At the White House coronavirus task force briefing on Monday, President Donald Trump said that he and his team have discussed the possibility of a national stay-at-home order but he said that it’s “pretty unlikely” at this time.

In an interview on NBC’s “TODAY” show on Wednesday, Surgeon General Jerome Adams said the U.S. is under a system of federalism where governors can make their own decisions. But when asked what he would say to the governor of Florida, who at that point had not yet issued a stay-at-home order, Adams said that the social distancing guidelines issued by the White House “are a national stay-at-home order.”