Despite pleas from governors, members of Congress and presidential candidates, President Trump initially had resisted using his powers under the Defense Production Act as officials look to ramp up the American medical system's capacity in anticipation of a spike in demand due to the coronavirus pandemic.

But the president then said Friday that he would in fact use the act to mobilize the private sector to provide medical equipment -- largely masks -- that health care professionals need to treat patients infected with the coronavirus. The Associated Press reported that Trump made the order to begin using the act after Senate Minority Leader Chuck Schumer pleaded for him to do so on Friday.

On Wednesday, Trump first invoked the Defense Production Act, the Korean War-era statute that allows the president to direct manufacturers to make certain equipment that is necessary for the United States to deal with a crisis, whether that be a war or a pandemic, in order "to promote the national defense." But as of Friday morning, he had not actually taken action under the law, tweeting Wednesday that he only signed the act "should we need to invoke it in a worst case scenario in the future. Hopefully there will be no need...."

That concerned officials across the political spectrum who see an immediate need for things like personal protective equipment (PPE) for medical professionals who will be treating patients sick with the novel coronavirus. A potential shortage has concerned medical professionals and even led multiple TV medical dramas to donate the masks they use in their wardrobe to hospitals.

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Trump was asked about what he might do under the Defense Production Act Thursday by Massachusetts Gov. Charlie Baker, a Republican.

"I just have two things on the PPE issue which obviously is a huge issue for all of us," Baker said on a teleconference the Trump administration held with governors. "The first is, it's just a little bit about the guidance you're going to offer ... some guidance on how the implementation of the Defense Production Act is going to work with respect to trying to man up and generate initial capacity around this PPE stuff."

Trump turned to Vice President Pence, who is heading up the White House Coronavirus Task Force, to answer Baker's question. He pointed to a desire to let U.S. firms cooperate voluntarily as long as that is possible.

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"I think, Mr. President, you put it well when you talk about the spirit in American business about wanting to ramp up voluntarily to meet the needs that our health care providers have in this country is truly inspiring," Pence said. "And so the president has not yet exercised his authority under the Defense Production Act. He said he will if he needs to. But I think ... the president's perception, the team's perception is now as American industry is stepping forward very aggressively."

Maryland Gov. Larry Hogan, the chairman of the National Governors Association and also a Republican, seconds later continued to prod Trump on the production of medical equipment, specifically protective equipment for those treating coronavirus patients.

He asked Trump for "some guidance on implementation of the Defense Production Act so we can kind of help work with [Health and Human Services] Secretary [Alex] Azar and give some thoughts about how the states could be more involved in helping that with some industries in our state."

Democrats, meanwhile, have taken direct swipes at the president for not immediately exercising his powers under the act -- a point of continuing partisan strain even as both parties are working together on legislation to aid Americans affected by the crisis.

"What is going on here, President Trump?" Senate Minority Leader Chuck Schumer, D-N.Y., tweeted late Thursday night. "We called on you to invoke the Defense Production Act. But in addition, we expect you to use it immediately. Why aren’t you using this authority now to make testing kits, masks, beds, ventilators?"

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Democratic presidential candidates Bernie Sanders and Joe Biden also publicly implored Trump to ramp up supply under the Defense Production Act.

In a statement Wednesday, Biden said Trump should "[p]rioritize and immediately increase domestic production of any critical medical equipment required to respond to this crisis" under the Defense Production Act.

The former vice president followed that statement with a tweet Thursday urging Trump to use his Defense Production Act powers.

"Yesterday, President Trump said he was invoking the Defense Production Act, then turned around and said he wasn't planning to use it," Biden said. "The President should exercise these powers now. We need more ventilators, protective equipment, and critical supplies. We need action, not words."

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"Lives are at stake. Trump must start taking this national emergency seriously," Sanders tweeted Thursday. "Without delay, we need to use the Defense Production Act to mass produce and distribute urgently needed medical equipment to every state and territory in America."

Others including House Speaker Nancy Pelosi, D-Calif., also urged the president to use the Defense Production Act Thursday as medical leaders were sounding the alarm over anticipated shortages caused by the coronavirus pandemic.

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"There are dwindling supplies of N95 respirators, isolation gowns, isolation masks, surgical masks, eye protection equipment, intensive care unit (ICU) equipment and diagnostic testing supplies in areas that had the first community outbreaks," a Thursday letter from the American Hospital Association, American Medical Association and American Nurses Association to congressional leaders said.

The letter, first reported by NBC News, asks for $100 billion in direct funding to hospitals, doctors, nurses and others on the frontline of the coronavirus pandemic.

"It is clear that COVID-19 will test the capacity of America's health care system," the letter said.

Fox News' Adam Shaw contributed to this report.