U.S. textile and garment companies that normally make sweatshirts or fabric for patio umbrellas are changing tack in the coronavirus pandemic, heeding a White House call to step up production of urgently needed surgical masks and gowns.

American Giant, a maker of flannel shirts, sweatshirts and jeans, switched two of its North Carolina plants over to masks, joining a group of a dozen companies organised by the National Council of Textile Organizations (NCTO) lobby group.

"Week one, we expect to make 35,000 masks and then ramp it up from there. We are laser-focused on masks right now," Bayard Winthrop, the San Francisco-based company's chief executive officer, said on Monday. "We're going to start shipping as soon as we can fill a truck."

Doctors across the United States have been struggling with low supplies of surgical masks and other protective equipment as they scramble to fight a highly contagious disease that has infected nearly 44,000 Americans and killed more than 500.

The industry effort aims to ramp up to producing 10,000 masks per week, according to the NCTO, which represents the $76.8 billion industry.

The move to assist with the public health crisis comes from an industry that has weathered a long decline over the past few decades as production of most U.S. apparel and a wide range of textile products has shifted from the southeastern United States to other countries, primarily China.

The decline prompted many of the nation's remaining mills and garment makers to focus on technical products, including military uniforms, domestic production of which is protected by federal law.

Allen Gant, chief executive of the textile maker Glen Raven Inc, which makes high-tech fabrics including Sunbrella used in patio furniture, said his company was also joining the effort.

"Let me tell you what, this is a Herculean effort in our entire industry," Gant said from his office in Burlington, North Carolina. "We've started working around the clock making masks, sheets, pillow cases and curtains for hospitals."

NCTO Chief Executive Kim Glass is leading the charge to get companies normally in stiff competition to unite.

"We've never seen such cooperation before," Glass said. "Everyone is stepping up, companies large and small. This is new."