White House coronavirus task force member Dr. Anthony Fauci on Tuesday pushed back on President Trump’s optimistic projection of soon reopening the nation’s economy — saying the US still lacks enough coronavirus testing materials and tracing procedures to make that possible.

“We have to have something in place that is efficient and that we can rely on, and we’re not there yet,” Fauci said in an interview with the Associated Press.

The comments by the head of the National Institute of Allergy and Infectious Diseases come as Team Trump weighs how quickly businesses can reopen and Americans can get back to work.

The president has mentioned the possibility of reopening some parts of the country by May 1 and said he could announce recommendations by this week.

During Monday’s coronavirus briefing at the White House, Trump claimed “total authority” over when to relax restrictions and restart the economy.

Fauci said a May 1 target was “a bit overly optimistic” for many areas of the US, adding that any easing off social-distancing rules would have to occur on a “rolling” basis, not all at once.

His main concern is that a premature reopening would bring new outbreaks in areas where social distancing has eased, but public health officials don’t yet have the means to rapidly test for the virus, isolate new cases and track down everyone whom an infected person came into contact with.

“I’ll guarantee you, once you start pulling back, there will be infections. It’s how you deal with the infections that’s going count,” Fauci told the AP.

The key is “getting people out of circulation if they get infected, because once you start getting clusters, then you’re really in trouble,” he said.

Fauci — who on Monday said he had used “a poor choice of words” in a CNN interview that prompted Trump to retweet a #FireFauci hashtag — told the AP that the president’s lengthy news briefings were “really draining.”

“If I had been able to just make a few comments and then go to work, that would have really been much better,” he told the news outlet. “It isn’t the idea of being there and answering questions, which I really think is important for the American public. It’s the amount of time.”

Much of the 79-year-old’s time outside the briefing room is focused on analyzing progress on blood tests that aim to reveal who was exposed to the coronavirus by spotting antibodies their immune systems formed to fight back.

The tests will be crucial in determining when and how people can return to work, but Fauci cautioned that most of the tests have not yet been proven to work well.

Fauci said his staff has been working with the Food and Drug Administration to validate the serology tests, which check for proteins in the immune system through a blood sample.

The presence of proteins means a person was exposed to the coronavirus and developed antibodies against it, which may mean the person has at least some immunity.

Fauci and his team are seeking to prove what level of antibodies it takes to really be immune; if particular types of antibodies are vital rather than an overall level; and how long that protection lasts.

“We’re going to have to find out the answer to all of those questions,” Fauci said. “I know people are anxious to say, ‘Well, we’ll give you a passport that says you’re antibody-positive, you can go to work and you’re protected.’”

He added: “The worst possibility that would happen is if we’re actually wrong about that” and those people get infected.

Scientists also still don’t fully understand how often people who show either no obvious symptoms or very few symptoms are spreading the virus.

It’s “purely a guesstimate,” but no less than 25 percent and no more than half of overall cases may be from the relatively asymptomatic, he said.

Fauci said a second wave of infection isn’t inevitable.

But he added: “If you mean it goes way down and then come September, October, November, we have another peak, I have to say I would not be surprised. I would hope that if and when that occurs, that we jump all over it in a much, much more effective way than we have in these past few months.”

On Monday, he said he was not criticizing Trump when he said an earlier US shutdown would have saved lives, adding that the president listened to his recommended restrictions.

After Trump tried to shoot down a New York Times article that said he was slow to react to his team’s recommendations about the pandemic, the president gave Fauci a vote of confidence.

White House spokesman Hogan Gidley also said the doctor would not be fired.