The move to activate the Korean War-era emergency law came the same day that Trump slammed GM on Twitter after reports emerged that his administration had called off a deal to buy tens of thousands of ventilators that GM agreed to produce in partnership with a ventilator manufacturer. It marks a pivotal turn in Trump's previous reluctance to put the DPA into use.

“As usual with ‘this’ General Motors, things just never seem to work out,” Trump tweeted. “They said they were going to give us 40,000 much needed Ventilators, ‘very quickly’. Now they are saying it will only be 6000, in late April, and they want top dollar. Always a mess with Mary B. Invoke ‘P’.”

The tweet came the morning after The New York Times reported that a deal between GM and medical device supplier Ventec to provide up to 80,000 ventilators was called off after FEMA said it needed more time to assess how much the ventilators would cost.

Minutes after the first tweet, Trump called on GM to reopen its recently shuttered auto plant in Lordstown, Ohio, to begin producing ventilators.

“General Motors MUST immediately open their stupidly abandoned Lordstown plant in Ohio, or some other plant, and START MAKING VENTILATORS, NOW!!!!!!,” he tweeted. “FORD, GET GOING ON VENTILATORS, FAST!!!!!! @GeneralMotors @Ford”

In a statement, GM said it, Ventec and its suppliers have been "working around the clock for over a week to meet this urgent need. Our commitment to build Ventec’s high-quality critical care ventilator, VOCSN, has never wavered."

Trump’s move comes amid rising criticism from Congressional Democrats and governors from states hard-hit by the virus outbreak, who have blamed Trump for not invoking the DPA sooner. Illinois Gov. J.B. Pritzker, whose state has more than 3,000 coronavirus cases, praised Trump's decision but said that more federal support will be needed.

"That’s terrific, but we need more," Pritzker said. "We need thousands more ventilators, as many as we can in short order. As you hear time and time again, you’re competing against everybody all the time.”

Trump’s decision to invoke the DPA caps more than a week of false starts with the emergency law, which allows the president to direct private industry to produce needed goods in a crisis. Trump first activated the DPA with an executive order March 18, but said he would use it only if necessary.

As recently as Thursday night, Trump was downplaying the need for more ventilators in an appearance on Fox News. “I have a feeling that a lot of the numbers that are being said in some areas are just bigger than they’re going to be,” he told Sean Hannity. “I don't believe you need 40,000 or 30,000 ventilators. 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?’”

At a press conference Friday evening, Trump repeated his claim that GM lowered its ventilator offer in negotiations with the White House and implied that he invoked the DPA in response.

“We thought we had a deal for 40,000 ventilators, and all of a sudden, it became six [thousand] and price became a big object,” Trump said. “But Peter Navarro is going to handle that … Maybe they'll change their tune. But we didn't want to play games with them.”

The president also said his previous opposition to GM’s decision to shutter an auto plant in Lordstown, Ohio, made negotiations with the automaker difficult.

“I was extremely unhappy with Lordstown, Ohio, when they left Lordstown, Ohio, in the middle of an auto boom,” Trump said, adding later “and frankly, I think that would be a good place to build the ventilators.”

Appearing on CNN Friday, Michigan Gov. Gretchen Whitmer said she knows GM will "rise to the challenge," but that it "won't happen overnight. Switching over from building cars to building something as complicated as a ventilator is going to take a while, and we don't have a lot of time to waste."

"That's why I'm glad to see this action. I would love to see more of this, more of the strategic powers of the president to be used nationally. We need a national strategy. This patchwork of laws based on who the governors are really isn't the best strategy going forward," she said.