President Donald Trump took aim at General Motors and Ford Motor on Twitter Friday.

Trump tweeted just before noon a demand that the carmakers start making critical-care ventilators immediately.

Minutes after the tweets, GM made it official that it will build the FDA-cleared ventilators at its plant in Kokomo, Indiana, and they're scheduled to ship as soon as next month. GM said that is in addition to medical device manufacturer Ventec Life System's ramp-up at its factory in Bothell, Washington.

GM will begin manufacturing FDA-cleared surgical masks at its Warren, Michigan, facility, which used to make transmissions but was idled as part of a restructuring last year.

Production will start next week and within two weeks increaseto 50,000 masks per day, with the potential to increase to 100,000 per day.

GM CEO Mary Barra said that since partnering with Ventec on March 20, GM's employees in all areas have "moved mountains to find real solutions to save lives and fight the pandemic" in seven days.

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In a string of tweets, Trump said, "As usual with 'this' General Motors, things just never seem to work out. 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'."

He then tweeted, "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!!!!!!"

Trump explained, "Invoke 'P' means Defense Production Act!"

It wasn't immediately clear what Trump meant by bringing up the Defense Production Act. He has already invoked its authority during the coronavirus crisis, but his administration has taken no steps toward formally ordering privately held firms to begin producing supplies or prioritize government contracts.

He said Sunday that the threat of invoking it seemed to be working, raising the possibility that the president's posts on Twitter might be intended in the same way and stopping short of ordering productions. "We're a country not based on nationalizing our businesses," Trump said Sunday.

The Lordstown comment refers to GM's decision in November 2019 to permanently idle its factory in Lordstown, Ohio, that had built the Chevrolet Cruze compact car.

Trump had urged Barra to change her mind and keep it open, but the last Cruze rolled off the line around this time last year.

GM sold the facility to electric truck maker Lordstown Motors.

Rachel McCleery, a Washington-based spokeswoman for Ford's government affairs, said, “Ford is pulling out all the stops to quickly and safely provide vitally needed equipment for patients, first responders and health care workers.

"We have started delivering tens of thousands of Ford-produced face shields to hospitals and police agencies, including the NYPD," McCleery said. "We have teams working flat-out with GE Healthcare to boost production of simplified ventilators, and with 3M to increase the production of powered air-purifying respirators. Ford is in active conversations with the administration, seeking guidance about approvals, scope and distribution relating to a series of products, including ventilators."

Ford will provide more detail on timing and production figures as soon as possible, McCleery said.

GM said it will deploy about 1,000 workers to scale production of the ventilators immediately. It has worked with United Auto Workers to bring in employees from the Kokomo plant and Marion Metal Center in Marion, Indiana.

GM is delivering the necessary machinery to the Warren plant Friday, it said. The "employee-led initiative was created, planned and approved in about 48 hours," GM said in a statement. It involves GM’s traditional supply base and new partnerships specific to the medical device industry. GM will collaborate with governments and local suppliers to distribute the masks.

Trump tweeted that the government "just purchased many Ventilators from some wonderful companies. Names and numbers will be announced later today!"

This week, Ford said it will join the effort to "speed production" of respirators by collaborating with 3M to manufacture "Powered Air-Purifying Respirators." The two are working on a "new design leveraging parts from both companies," a statement said.

It is possible Ford will produce the new respirator in a Ford facility in Michigan.

Ford engineers use parts that are used in the F-150 pickup.

Staff writer Phoebe Wall Howard and Todd Sprangler contributed to this report. Contact Jamie L. LaReau at 313-222-2149 or jlareau@freepress.com. Follow her on Twitter @jlareauan.

This article originally appeared on Detroit Free Press: Trump bashes GM and Ford on Twitter, demands they make ventilators