Donald Trump has demanded Ford and General Motors pivot to making ventilators that could save lives amid the coronavirus outbreak in the United States, in a tweet urging the Chevrolet maker to re-open an Ohio assembly plant the company no longer owns.

The demand follows just one day after a report indicated the White House had decided earlier in the week to curb a plan for General Motors to begin making those lifesaving devices, amid concerns that the $1 billion price tag for making them was simply too high.

"General Motors MUST immediately open their stupidly abandoned Lordstown plant in Ohio, or some other plant, and START MAKING VENTILATORS, NOW!!!!!! FORD, GET GOING ON VENTILATORS, FAST!!!!!!" Mr Trump wrote on Twitter, referencing the plant that General Motors announced it had sold in November. Mr Trump wrote in a later tweet that the US government had purchased many ventilators, and that he planned on releasing the details on Friday.

The cancelled deal, reported by the New York Times, was to be announced on Wednesday at the White House, and would have teamed General Motors up with the medical equipment maker Ventec Life Systems to make as many as 80,000 ventilators, which are in critical short supply across the country as the pandemic has spread and multiplied.

But officials say that the Federal Emergency Management Agency (FEMA) stopped the plan fearing that the cost — a total of $1 billion with millions paid up front to General Motors to retool a plant in Indiana — would prove prohibitive. Those officials indicated that the car maker had also revised a promise of 20,000 ventilators to be made quickly down to 7,500. The deal could still go through, as well, but FEMA is currently working with the US military to sort through alternative proposals.

Meanwhile, New York governor Andrew Cuomo has criticised the president for his response to the pandemic, including the decision to only send the state 4,000 ventilators from the country's strategic reserves — which Mr Cuomo has charged falls far short of the tens of thousands his state will need in the coming days, weeks and months.

Mr Trump, meanwhile, told Fox News's Sean Hannity on Thursday night that he does not think

“I don’t believe you need 40,000 or 30,000 ventilators,” Mr Trump said during that interview. “You go into major hospitals sometimes, and they’ll have two ventilators. And now all of a sudden they’re saying, ‘Can we order 30,000 ventilators?’”