Donald Trump has been accused of using another White House coronavirus task force briefing to broadcast a “campaign ad” in which New York Governor Andrew Cuomo, one of his most trenchant critics, appeared to shower him with praise.

The US president dimmed the lights and played two selectively edited videos on screens behind the briefing room podium featuring Cuomo, whose state has been hardest hit by the deadly pandemic.

“What the federal government did, working with states … was a phenomenal accomplishment,” the governor said in the first clip. “These were just extraordinary efforts and acts of mobilisation, and the federal government stepped up and was a great partner, and I’m the first to say it. We needed help and they were there.”

But the films were played just two days after Cuomo, who has emerged as one of the most prominent Democrats during the crisis, eviscerated Trump in scathing 15-minute remarks. “First of all, if he’s sitting home watching TV, maybe he should get up and go to work, right,” he told reporters on Friday. “Second, let’s keep emotion and politics out of this and personal ego if we can because this is about the people and our job and let’s try to focus on that.”

Cuomo acknowledged that Trump had moved quickly to increase hospital capacity, but said he was wrong to claim the city’s Javits Center, a convention facility converted to a hospital, had not been used, pointing out that 800 people had gone through. The projected number of patients “were the president’s projections”, he added.

Exasperated, Cuomo went on: “The president doesn’t want to help on testing. I said 11 times, I said the one issue we need help with is testing. He said 11 times: ‘I don’t want to get involved in testing, it’s too complicated, it’s too hard.’ I know it’s too complicated and too hard. That’s why we need help. I can’t do an international supply chain.

“He wants to say: ‘Well I did enough.’ Yeah, none of us have done enough. We haven’t, because it’s not over … We have a lot more to do and no one can do the posture of ‘Just say thank you for what I’ve done, and I’m now out, I’m not doing anything else. I’ve done my part.’”

The pair of New Yorkers exchanged barbs on Twitter but, at Sunday’s briefing, Trump was only eager to bask in Cuomo’s praise. After the first video was shown, he chided his staff: “They left out the good part. Good job, fellas … You want to put the rest of it up, or do you not have it?”

He added: “I just think it’s so good for people because it’s bipartisan. This is not about Democrats, Republicans. This is about a thing that hit our country, the likes of which has never happened to us before.”

The second clip was duly played later in the briefing. And earlier Trump had read aloud from a Wall Street Journal column praising him. A CNN reporter asked, with more than 22 million Americans unemployed and the death toll now above 40,000, “is this really the time for self-congratulations?”.

Trump retorted: “You’re CNN, you’re fake news … You don’t have the brains you were born with.”

Media reports suggest Trump is ready to transition from crisis mode to a new phase focused on economic recovery and his re-election.

For his part, Cuomo issued two pointed tweets on Sunday evening. One said: “‘Everyone is entitled to his own opinion, but not his own facts.’ — Senator Daniel Patrick Moynihan.” The other thanked health care, hospital and nursing home workers, and said: “You are heroes. #NewYorkTough.”

Trump’s publicity stunt also drew direct criticism. Walter Shaub, former director of the Office of Government Ethics, tweeted: “Beyond being another taxpayer-funded campaign ad, this video clip also makes Trump look exceedingly weak. The video casts Cuomo as Trump’s boss giving him a performance appraisal. (If only!).”

The president also sought to downplay the national testing shortage, despite governors’ complaints that they lack sufficient capacity to safely reopen their economies. And he became visibly angry when questioned why he had still been holding campaign rallies in February rather than warning Americans about the virus.

Challenged repeatedly by Weijia Jiang of CBS News, he demanded: “Who are you with? … nice and easy, nice and easy, just relax … Keep your voice down, please. Keep your voice down.” Touting his partial travel restrictions on China, he insisted: “You should say, ‘Thank you very much for good judgment.’”

Away from the virus, Trump was questioned on whether he would consider pardoning allies Michael Flynn and Roger Stone, who were caught in the justice department’s Russia investigation. “The top of the FBI was scum,” he complained bitterly. “They’re human scum.”

US governors have accused Donald Trump of making “delusional” and “dangerous” statements amid mounting tensions between the president and state leaders over coronavirus testing and pressure to roll back stay-at-home measures.

The United States has by far the world’s largest number of confirmed coronavirus cases, with more than 730,000 infections and over 39,600 deaths.

Many state leaders have said they cannot embark on Trump’s recommended three-phrase programme to ease stay-at-home restrictions without a robust and widespread system of testing in place.

Researchers at Harvard University have suggested the US should conduct more than three times the number of coronavirus tests it is currently administering over the course of the next month, the New York Times reported.

Democratic governor Ralph Northam of Virginia told CNN on Sunday that claims by Trump and Vice-President Mike Pence that states have plenty of tests were “just delusional”.

“We have been fighting for testing,” he said on CNN’s State of the Union. “We don’t even have enough swabs, believe it or not. For the national level to say that we have what we need, and really to have no guidance to the state levels, is just irresponsible, because we’re not there yet.”

Maryland, Virginia and Washington DC are still seeing increasing cases even as the center of the US outbreak, New York, has started to see some declines. Boston and Chicago are also emerging hot spots with recent surges in cases and deaths.

“The administration I think is trying to ramp up testing, they are doing some things with respect to private labs,” said Republican governor Larry Hogan of Maryland during a CNN interview. “But to try to push this off, to say the governors have plenty of testing and they should just get to work on testing, somehow we aren’t doing our jobs, is just absolutely false.”

Several states, including Ohio, Texas and Florida, have said they aim to reopen parts of their economies, perhaps by 1 May or even sooner, but appeared to be staying cautious.

The White House guidelines released late last week on reopening the economy recommend a state record 14 days of declining case numbers before gradually lifting restrictions. Yet in a series of tweets from Trump on Friday, the president called for the “liberation” of Minnesota, Michigan and Virginia, Democratic-led states with strict stay-at-home orders, and appeared to be the catalyst for protests backed by rightwing groups in several places, including Texas, Maryland and Ohio.

In his tweet on Friday the president claimed without evidence that Virginia citizens’ second amendment rights were “under siege” after Northam signed into law tighter firearms restrictions a week earlier.

In Austin, the Texas state capital, protesters called on Trump to fire Dr Anthony Fauci, the leading US expert on infectious diseases, from his task force tackling the pandemic crisis.

Washington governor Jay Inslee, a Democrat who on Friday blasted Trump’s tweets as “unhinged rantings”, and one of the most vocal critics of the president, reinforced his position on Sunday.

“I don’t know any other way to characterize it,” Inslee told host George Stephanopoulos on ABC’s This Week. “To have an American president encourage people to violate the law, I can’t remember any time during my time in America where we have seen such a thing. And it is dangerous because it can inspire people to ignore things that actually can save their lives.

“It is doubly frustrating to us governors because this is such a schizophrenia. The president is basically asking people, ‘Please ignore Dr Fauci and Dr Birx [White House taskforce medical advisers], please ignore my own guidelines that I set forth,’ because those guidelines made very clear… that you cannot open up Michigan today, or Virginia, under those guidelines. You need to see a decline in the infections and fatalities. And that simply has not happened yet.”

Pence insisted in an interview aired on NBC’s Meet the Press on Sunday that the country had “sufficient capacity” for any state to go to the phase one level.

But Hogan and others said the issue was not as straightforward as Pence presented it.

“Every governor in America has been pushing and fighting and clawing to get more tests, not only from the federal government, but from every private lab in America and from all across the world. It’s not accurate to say there’s plenty of testing out there, and the governors should just get it done.”

Hogan said he was sympathetic to the protesters. “I’m frustrated also,” he said. “But I don’t think it’s helpful to encourage demonstrations. To encourage people to go protest the plan that you just made recommendations on, it just doesn’t make any sense. We’re sending completely conflicting messages out to the governors and to the people, as if we should ignore federal policy and federal recommendations.”

Gretchen Whitmer, the Democratic governor of Michigan, where some of the earliest protests took place last week, once again strongly defended strict lockdown restrictions in her state, the 10th largest by population but third highest in the nation in terms of Covid-19 deaths.

“My stay-home order is one of the nation’s more conservative but the fact of the matter is it’s working. We are seeing the curve start to flatten and that means we’re saving lives,” she said.

“[But] I can tell you, we could double or even triple the number of tests if we had the swabs and reagents. That’s precisely why it would really be incredibly helpful if the federal government would use the Defense Production Act to start making these swabs and reagents, so we can improve testing.”