President Trump should use the Defense Production Act to ramp up the country's domestic production of medical masks, gowns and other items crucial for health care workers to fight the novel coronavirus, the American Hospital Association, American Medical Association and American Nurses Association wrote in a letter on Saturday.

Why it matters: Officials on the White House coronavirus task force had no firm answers on Saturday when asked when doctors and nurses across the country can expect to receive face masks to protect themselves while treating patients with COVID-19.

What they're saying: "Even with an infusion of supplies from the strategic stockpile and other federal resources, there will not be enough medical supplies, including ventilators, to respond to the projected COVID-­19 outbreak. We have heard of health care providers reusing masks or resorting to makeshift alternatives for masks," the agencies write to the president.

The other side: "The President has invoked the Defense Production Act to ensure that the necessary authorities will be available to prioritize production of items under government contracts and to allocate scarce items where they are needed most. He is currently using it to drive the private-sector’s response to this crisis," a White House official told Axios' Alayna Treene.

"And the private-sector’s response, to date, to his direction has been overwhelming, fulfilling government-identified needs faster than anyone thought possible," the official added.

Go deeper: Defense Production Act: What you need to know