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President Donald Trump on Friday announced a new series of measures to combat the coronavirus and treat those who are affected, while pushing back on criticism that his administration was unprepared to confront the pandemic.

Speaking in the White House Rose Garden, Trump declared a national emergency that could free up $50 billion to help fight the pandemic and said that he was empowering the secretary of Health and Human Services to waive certain laws and regulations to ensure the virus can be contained and patients treated.

"To unleash the full power of the federal government … I am officially declaring a national emergency," Trump said.

"Two very big words," he added.

Trump said the action would "open up access" to up to $50 billion "for states and territories and localities in our shared fight against this disease."

Flanked by Vice President Mike Pence, Health and Human Services Secretary Alex Azar and other top federal officials and corporate executives from companies such as Walmart, Trump said that the ability to waive certain laws and regulations would allow for easier admission to nursing homes and end limits on the length of hospital stays and the number of beds available.

He announced that 1.4 million new tests for the coronavirus would be available next week and that 5 million would be available within the next month — although he added that "I doubt we'll need that" quantity. He also said there were plans to allow "drive-thru" virus tests.

In an unusual and lengthy news conference, a parade of business leaders took turns speaking after Trump — before the president and other federal officials made additional key announcements related to the administration’s coronavirus response.

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Trump shook hands with several of those business leaders as he introduced them at the lectern — a breach of best practices recommended by public health experts across the United States.

After the corporate leaders spoke, Trump and other officials finally announced additional measures to confront the pandemic, which included the waiving of interest on federal student loans and the purchase of “large quantities” of oil for the U.S. strategic oil reserve. Officials also said they would be offering guidance to suspend all visitations to nursing homes, with exceptions being made only for end-of-life situations.

Nevertheless, the stock market — which had in recent days fallen 20 percent from its latest high, delving formally to bear territory — reacted favorably to the announcement.

The Dow Jones Industrial Average rose steadily as Trump spoke and closed for the day up nearly 2,000 points, or 9.4 percent.

Trump, seen in photographs to have been in close proximity with people who have since tested positive for the coronavirus, also suggested Friday he would “most likely” get tested for the disease.

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"Not for that reason, but because I think I will do it anyway," Trump said, when questioned by a reporter about standing next to an aide to Brazilian President Jair Bolsonaro at his Mar-a-Lago resort last weekend.

Trump had hinted Thursday that he was strongly considering taking emergency action, telling reporters in the Oval Office that he was thinking of invoking the Stafford Act to declare a national emergency.

A national emergency declaration from the president would effectively create access to billions in federal aid to help with the pandemic. Plans for the emergency declaration were first reported by Bloomberg News.

Under the Stafford Act, an "infectious disease emergency declaration" by the president would allow the Federal Emergency Management Agency to provide disaster relief funding to state and local governments, as well as federal assistance to support the coronavirus response. The law allows the agency to circumvent legal barriers to more quickly distribute such aid.

Emergency declarations are most often used in the event of natural disasters, but can also be applied to disease outbreaks.

The president had tweeted earlier about the Friday press conference amid the rapid spread of the virus and as the White House has scrambled to craft a strategy to shift Trump's response to the outbreak, which had been focused on downplaying the threat and accusing the media of creating undue concern.

Trump has come under increasing fire in recent weeks over his response to the outbreak while his administration weathered criticism for the lack of coronavirus testing being done compared with other countries.

Asked Friday at his press conference by NBC News’ Kristen Welker whether he should take responsibility for the failure to disseminate larger quantities of tests earlier, Trump declined.

"I don't take responsibility at all,” he said.

Trump also responded testily to a question from another reporter about a decision made by the administration in 2018 to disband the White House’s National Security Council Directorate for Global Health Security and Biodefense — a unit sometimes referred to as the White House pandemic office.

Trump called the question “nasty” and replied, “I didn’t do it.”

“You say we did that, I don't know anything about it,” Trump said.

In addition to having insisted for weeks that he had the outbreak under control, Trump has also propagated personal beliefs about the coronavirus that contradict those of veteran health officials and experts.

As panic began to set in over the outbreak, Trump tried to quell the fears of Americans across the country by giving a speech from the Oval Office on Wednesday night. He announced that he would ban many foreign travelers from Europe for the next 30 days and offered a series of economic relief actions to help workers and companies deal with the outbreak. But his speech was met with swift pushback after he misstated several aspects of the policy and failed to propose any new action to combat the outbreak domestically.

Health officials in recent days have sounded the alarm, warning the public that the outbreak is likely to get worse. Many major public events, including all NBA, NHL, MLB and Major League Soccer preseason games and Broadway shows, have been canceled this week, and Thursday saw the Dow's worst day since the 1987 crash.

Wall Street, however, rallied Friday, bouncing firmly back after lawmakers and the White House appeared close to finalizing an economic relief package to address the coronavirus pandemic.