President Trump is increasingly dismissing the consensus of health experts, scientists and some of his Republican allies that widespread testing is key to the safe end of restrictions meant to slow the spread of the deadly coronavirus, saying Friday that “testing isn’t necessary” and is an imperfect guide.

The president has played down the need for testing as he overrides public health recommendations that would prolong the closures of schools, businesses and much of daily life. Although he is now tested every day with a rapid-result machine, Trump has questioned the value of extensive testing as the gap between available capacity and the amount that would be required to meet public health benchmarks has become clearer.

Trump’s comments came as a second employee in the White House complex tested positive for the coronavirus, a development that prompted increased testing for staff and other precautions not generally available to most Americans.

“This is why the whole concept of tests aren’t necessarily great,” Trump said at the White House, as he confirmed a positive test result “out of the blue” for a top staffer, Vice President Pence’s press secretary, Katie Miller.

During a Friday morning interview on Fox News, Trump ticked approvingly through the current testing figures but did not say what level he thinks is optimal or safe to use as a national benchmark for economic reopening.

Asked about the positive test result for one of his Navy valets, the president said that he himself remains negative but that the valet’s experience is instructive.

“And this is why testing isn’t necessary. We have the best testing in the world, but testing’s not necessarily the answer because they were testing them,” Trump said of the staff members.

Data shows that the country has slowly ramped up testing. Since late April, the nation has tested about 250,000 people per day on average, according to the COVID Tracking Project. On Thursday, that number hit a high of 318,720 reported tests.

Still, many public health experts say those numbers are far below what will be necessary before schools and businesses can reopen with confidence, and before Americans can return en masse to travel, work and social gatherings.

On Thursday, Harvard University researchers published new estimates, showing that the United States needs to be conducting at least 900,000 tests daily by May 15 — roughly triple the current rate — to have a better grasp of the outbreak. They found that fewer than a dozen states are currently testing enough to get ahead of the virus that has claimed the lives of more than 76,000 Americans with nearly 1.3 million cases reported.

“The bottom line remains: We need a lot more testing,” the researchers wrote.

Other researchers have estimated that the United States will need to scale up testing far more dramatically — conducting anywhere from 3 million to 25 million tests a week — to understand the true scope of the pandemic and to be able to quickly identify and snuff out localized outbreaks.

Ashish Jha, director of the Harvard Global Health Institute, has also said that the volume of tests alone is not the only worthwhile metric. It also matters what populations are — or aren’t — getting tests and whether the government can put in place adequate contact tracing for those who are infected.

In addition, he and other public health experts say, if communities relax social distancing too early or too aggressively, more tests might be necessary quickly in case the virus begins its spread again.

“The moment you relax, the number of cases will start climbing,” Jha said in an announcement about Harvard’s latest estimates. “And therefore, the number of tests you need to keep your society, your state, from having large outbreaks will also start climbing.”

More than 40 states are in some phase of lifting restrictions, most with Trump’s blessing and none in full accordance with guidelines developed by the White House coronavirus task force he empaneled.

Georges Benjamin, executive director of the American Public Health Association, said that without widespread testing, the nation faces a “recovery that is fraught with enormous hazards. You cannot have public confidence that people can go out and be around one another. You’ll have to repeatedly close things down.”

Congress provided $25 billion for testing in the most recent emergency relief bill, and House Democrats are expected to unveil a massive new measure as soon as next week with testing-related provisions.

A recent House Democratic memo identified a need for a “public comprehensive testing plan” with firm benchmarks and timelines for test frequency, supply availability and laboratory capacity, as well as a mandate to require public reporting on all testing results. Many Democrats are pressing for even more aggressive action to federalize the medical supply chain.

“Congress should develop a national program to track, identify, and isolate all possible traces of this disease. If we attempt to reopen this country without a sweeping approach that matches the magnitude of the crisis, more Americans will unnecessarily die,” said the memo, prepared by the House Energy and Commerce Committee.

House Speaker Nancy Pelosi (D-Calif.) said on a Wednesday call with reporters that the next House coronavirus relief bill would be focused on “testing, tracing, treatment and isolation.”

The concern about the lack of testing has crossed party lines.

“We can’t continue to pump federal dollars and print federal dollars to keep the economy afloat if we’re not allowing the engine of the economy to begin to spin again. But we can’t do that without adequate testing,” said Rep. Michael C. Burgess (R-Tex.), a conservative physician, during a Friday House committee briefing.

The House Democratic proposal is the first step in the process, and it is unclear what final measure will emerge from Congress.

Sen. Lamar Alexander (R-Tenn.), chairman of the Senate health committee, has been one of the most outspoken members of Congress in calling for more testing, but he has assiduously avoided criticizing the Trump administration for its handling of the issue.

“The United States, according to Johns Hopkins and President Trump, has tested 7 million Americans — more than any country; more per capita, for example, than South Korea, which we often admire for the way it has dealt with covid–19,” Alexander said on the Senate floor Thursday.

“So we are testing a lot of people. But if we want to go back to work and we want to go back to school, we are going to need to have quick, reliable tests for everybody in the nursing home, everybody in the meatpacking plant, everybody maybe on the college campus, everybody in a graded school,” Alexander said.

In an op-ed last month with Sen. Roy Blunt (R-Mo.), Alexander said efforts to ramp up testing capacity in the United States were impressive but far from adequate. They proposed a “Shark Tank”-like competition for testing.

“There is no safe path forward to combat the novel coronavirus without adequate testing,” they wrote in The Washington Post.

The emergency bill that Trump signed on April 24 mandated that Health and Human Services Secretary Alex Azar had 30 days to report to Congress on a “strategic testing plan” — one that must include, among other things, a blueprint for increasing U.S. testing capacity, including the supplies needed to collect specimens and process them, and an outline of all federal resources available to states and local jurisdictions.

A spokesman for HHS said Friday that the department intends to deliver a testing plan as requested by Congress within the time frame allotted.

In appearances this week, Trump has defended the U.S. record on testing, calling it the “greatest testing in the world,” while playing down the importance of testing for the disease.

The president said he didn’t think “you need that kind of testing or that much testing,” he called testing “somewhat overrated,” and he told reporters that “in a way, by doing all of this testing, we make ourselves look bad.”

During a White House event with admiring Republican House members, Trump also returned to a widely criticized prediction that the coronavirus pandemic will disappear on its own.

“I feel about vaccines like I feel about tests. This is going to go away without a vaccine,” Trump said, a statement at direct odds with the physicians on his coronavirus task force. “It’s going to go away and it’s, we’re not going to see it again, hopefully, after a period of time. You may have some, some flare-ups,” in the fall or later, the president said.

“They die too,” Trump said of viruses.

Amy Goldstein contributed to this report.