But the administration's public health experts have no idea how bad the US coronavirus outbreak will get, since bottlenecks in lab testing and faults with diagnosis kits mean they can't know how many infections there really are.

"We are flying blind," warned Democratic Rep. Mike Quigley of Illinois, one of many lawmakers of both parties who emerged furious from a Capitol Hill briefing Thursday with government officials about the situation.

A source inside the meeting told CNN that lawmakers were told that only 11,000 tests had been conducted, prompting many to ask why South Korea can manage to test 10,000 in a single day.

The administration has been boasting for several weeks that it is sending millions of testing kits to states and local authorities. But those officials say long waits for kits and issues with the reagent used in diagnosis mean they are able to test only the most high-risk patients. They are left in the dark about the true extent of the coronavirus' spread through the community.

"Frankly, the testing has been going very smooth. If you go to the right agency, if you go to the right area, you get the test," Trump told reporters in the Oval Office.

But the President's comments contradicted his own government's head of infectious disease , Dr. Anthony Fauci, who admitted on Thursday that protocols under which doctors request tests for patients were not working.

"The system does not, is not really geared to what we need right now," Fauci said. "It is a failing. Let's admit it."

Ohio's director of public health, Dr. Amy Acton, warned in a news conference that a shortage of testing kits meant that it was impossible to accurately track the spread of the coronavirus through the state.

"We do have this virus amongst us in Ohio," she said, warning that once epidemiologists discover two cases of community transmission they assume that 1% of the population is already infected.

The number of confirmed cases of COVID-19 in the US has now passed 1,600, with more than 40 deaths, as more and more states declare states of emergency.

The fear of many health experts now is that the epidemic will grow so fast -- and in the dark, given the paucity of testing kits -- it will hit a peak that will all but overwhelm health services, as has happened in Italy.

Trump, however, is still pointing out that the US has lower infection rates than some other nations.

"I think we can say it for a lot of countries, for all countries hopefully. It goes away, it's going away. We want it to go away with very, very few deaths," the President said.

Worst health crisis in a 'century'

Hopefully the President is right. But his efforts to calm the markets and the American public with an Oval Office address on Wednesday evening failed spectacularly.

His message to Americans, after weeks of minimizing the pandemic, apparently to safeguard his political fortunes, contrasts sharply with the somber rhetoric of other world leaders.

British Prime Minister Boris Johnson steeled his people Thursday for a harrowing period ahead.

"I've got to be clear, we've all got to be clear -- this is the worst public health crisis for a generation," Johnson said. "I must level with you, level with the British public: More families, many more families, are going to lose loved ones before their time."

In France, President Emmanuel Macron said in a live televised address that the epidemic was "the most grave public health crisis that France has known in a century."

"Despite the efforts to slow it down, the virus continues to spread and is accelerating," he added.

US stock markets appear to share that grave assessment.

The Dow Jones Industrial Average crashed to its worst day since 1987 , dipping by 10% after a week of punishing losses, giving its own verdict on Trump's leadership.

Just a month ago, Trump was riding high after escaping impeachment and enjoying a divisive Democratic nominating race that looked set to stretch into the spring.

Now he is looking increasingly at odds with the reality of the situation. Having used up one key tool in his armory, the Oval Office address, only a display of competence by his government in fighting the epidemic seems capable of lifting the impression that he is an increasingly beleaguered President.

"There has been a sense of complacency on the part of the White House, the President in particular," David Gergen, an adviser to Republican and Democratic presidents, told CNN International.

Gergen warned that the coronavirus outbreak and its political implications was "more threatening to his presidency than impeachment."

The President, however, appeared sanguine on another issue -- his own health -- after an aide to Brazilian President Jair Bolsonaro , with whom he interacted over the weekend in Florida, had tested positive for novel coronavirus.

"Let's put it this way: I am not concerned," Trump said.

'Lack of trust'

Democratic presidential front-runner Joe Biden sought to exploit the White House's struggles and to offer Americans a vision of an alternative president.

Biden said the crisis had "laid bare the severe shortcomings of the current administration."

"Public fears are being compounded by a pervasive lack of trust in this President, fueled by the adversarial relationship with the truth he continues to have," the former vice president said in Delaware.

Among the mostly grim news on Thursday, there was one ray of light. House Speaker Nancy Pelosi and Trump's treasury secretary, Steven Mnuchin, appeared to be working well together despite the estrangement between House Democrats and the White House. They spoke multiple times on the phone and the two sides were closing in on a rescue package for the battered economy.

Senate Majority Leader Mitch McConnell, a Kentucky Republican, said the chamber would stay in town next week through a planned recess to work on the matter.

But the coming deal will not assuage frustration among lawmakers at the administration's botched testing approach.

Sen. Richard Blumenthal, a Democrat from Connecticut, said he was "absolutely appalled."

"There's still no plan, no strategy, for testing, for ventilators, for the basics that are required for people to survive," Blumenthal said. "We're talking about life and death, and there's still no plan."