President Donald Trump signed a memorandum Friday afternoon directing the Secretary of Health to “use any and all authority” to invoke the Defense Production Act that would force American automakers, General Motors and Ford, to produce ventilators amid the growing coronavirus pandemic.

“Our negotiations with GM regarding its ability to supply ventilators have been productive, but our fight against the virus is too urgent to allow the give-and-take of the contracting to process to continue to run its normal course,” the president said in a statement. “GM was wasting time.”

Hours earlier, Trump made a series of announcements on Twitter and expressed frustration at General Motors’ revised plan of providing fewer ventilators than originally planned.

Trump criticized General Motors CEO Mary Barra, saying the company promised to immediately deliver 40,000 ventilators but then rolled the number back to 6,000 and scheduled delivery for late April.

“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 said, later tweeting that he was referring to the Defense Production Act.

Trump also said the government had purchased “many ventilators from some wonderful companies” that would be announced later Friday.

Before the official White House memorandum was issued, some talking heads expressed confusion on social media about whether Trump’s Twitter statements should be considered an actual directive for the companies to begin work.

On Twitter, Trump also said that “thousands” of government-delivered ventilators were found in storage in New York that needed to be rolled out immediately.

Cities and states across the country have announced major shortages of masks, virus tests and ventilators as the number of coronavirus cases and deaths have accelerated with little signs of slowing.

Trump has previously refused to fully employ the law to ramp up the manufacture and distribution of critical supplies as hospitals, health officials and governors clamored for ventilators and other vital equipment.

The Defense Production Act was enacted in 1950 and allows the federal government to compel companies through loans and purchase commitments to develop specific equipment for national defense.

Trump, calling himself “a wartime president,” signed an executive order on March 18, declaring he was prepared to use the law, but has for the most part stopped short of any meaningful action.

During Thursday’s White House press briefing Trump said “we don’t need it” despite calls from both sides of the aisle to invoke the measure. “I just haven’t had to use it,” Trump said.

More than 100 former national security officials urged Trump in a letter Wednesday to use the act’s authority, saying it was necessary that government coordinate the effort and assign priorities to confront the crisis.

He has suggested that the government is coordinating with companies that have voluntarily offered to manufacture medical equipment and has compared using the act to “nationalizing our business.”