Updated: See the latest stories on the coronavirus outbreak.

Donald Trump on Friday declared a national emergency in response to the Covid-19 pandemic, but spent much of the announcement refusing to take responsibility for testing delays and praising his own inadequate response that helped let the coronavirus spread rapidly throughout much of the country.

Joined by representatives from major US companies like Walgreens and CVS, Trump unveiled a private-sector partnership to “vastly increase and accelerate our capacity to test for the coronavirus.”

He said half a million tests would be available by “early next week.” 

“We want to make sure that those who need a test can get a test very safely, quickly and conveniently, but we don’t want people to take a test if we feel that they shouldn’t be doing it,” he said.

The national emergency declaration will also allocate up to $50b (£40.7b) in disaster relief funding to states, effective immediately, Trump said.

The president and his administration have faced intense criticism for delays in testing for the new coronavirus. Many states have reported a backlog in testing or an inability to test people who suspect they have contracted the virus.

Coronavirus tests are alarmingly hard to come by, which the top infectious disease expert at the National Institutes of Health called “a failing” on Thursday.

Asked about the delays Friday, Trump defiantly said: “I don’t take responsibility at all.”

When asked about his demolition of Barack Obama’s pandemic response team, Trump called it “a nasty question.”

In announcing the increase in tests, Trump still appeared to downplay the public health crisis.

He said that five million tests would be available “within a month,” before adding: “I doubt we’ll need that.” 

Much of the testing capability is being provided by the private sector, such as the companies in attendance Friday, as well as large hospital systems and universities. Trump repeatedly praised the companies: for instance, Walmart for providing parking lot space for tests.

“There will be many more cases, but we’ll take care of that, and ultimately as the president said, this will end,” the NIH’s Dr Anthony Fauci said Friday. “But what’s going on here today is going to help it to end sooner than it would have.”

Trump also announced measures like the creation of a website where people could type in their symptoms and determine whether they should be tested, but details of how to access it will not be made available until Sunday evening.

For college students, most of whom are being forced out of campus housing as schools switch to remote learning, Trump said student loan interest rates would be waived. However, loan rates are currently very low, so it would have only a small impact on students facing financial burdens.

The White House has also reportedly pushed to classify top-level coronavirus meetings, a move that has hampered the government’s response to the outbreak.

Trump himself has created confusion and disseminated false information. During a primetime address on Wednesday, he issued a ban on European travel, but subsequently had to announce several clarifications. He has also frequently contradicted guidance from Fauci and the Centres for Disease Control and Prevention and downplayed the pandemic’s effects.

The travel ban was an illustration of the ways Trump has treated the coronavirus as a foreign invader rather than a domestic health crisis. He and his allies have used racist and nativist rhetoric to describe the pandemic, and much of his response has focused on closing borders and restricting travel rather than addressing problems within the US health care system.

Trump opened his press conference Friday by praising his response to the pandemic, claiming it was better “when compared to other places around the world,” touting “our closing of the borders” and claiming experts told him his ban on travel from China “saved a lot of lives.”

He also invited vice president Mike Pence to speak, who praised Trump’s “decisive action.”