Last month, a wireless store in New York City taped a paper sign outside its door that read: "In celebration of the second day of the Lunar New Year, any customer can get a mask for free today."

The offer was meant to attract shoppers to the storefront in Sunset Park, Brooklyn -- one of the largest Chinese enclaves in the United States -- as fears grew about the spread of coronavirus and pharmacies and online retailers began running out of face masks used to prevent its transmission.

Since then, the situation has become far more dire, with hundreds of deaths in China and more than two dozen countries reporting cases of the respiratory disease. On Friday, the World Health Organization warned of a global "chronic shortage" of equipment that could shield individuals from coronavirus.

"We're sending testing kits, mask, gloves, respirators and gowns to countries in every region. However the world is facing a chronic shortage of personal protective equipment," World Health Organization chief Tedros Adhanom Ghebreyesus said in a briefing in Geneva.

Coronavirus emerged in the city of Wuhan in central China in December. As of Friday morning, the number of confirmed cases globally stood at 31,420, with more than 31,000 of those in mainland China. There have been 638 deaths, all but two in China.

The worldwide mask shortage prompted electronics giant Foxconn, the maker of the Apple iPhone, to set up a production line of facial masks at its facility near Shenzhen in southeastern China.

The company said on Friday it is applying for product certification and it expects capacity to reach 2 million facial masks per day by the end of February.

"These masks will not only satisfy the maximum needs of company employees for preventing the coronavirus, but could also be used for external support to help with the current coronavirus control," the Taiwanese company said in a statement.

For weeks, it's been impossible to buy any masks on China's e-commerce giants. Even N95 respirators, which are said to be more effective than surgical masks in stopping transmission of the virus, are also out of stock on all major online platforms in China.

In Hong Kong, people have been waiting as long as three hours outside of pharmacies to buy surgical masks. Demand was so high that some pharmacies had to limit the number of masks customers were allowed to buy.

Across China, the spread of the virus has prompted quarantines, airline cancellations, stores closures and the temporary shut down of factories and other businesses.

In the Philippines, the government distributed free surgical masks to high school and college students after its first coronavirus case was confirmed on Febuary 1. Yet there are still mask shortages in medical supply stores in such major cities as Manila, Pagadian City, and Bukidnon.

Thailand on Tuesday curbed mask exports to ensure it has enough for its own citizens, according to multiple reports.

In France, a manufacturer of respiratory masks is ramping up production four or five times higher than normal. Kolmi Hopen typically produces 170 million masks a year at its facility in Angers, about 200 miles southwest of Paris. Now, though, demand for its products has multiplied, said Guillaume Laverdure, COO of parent company Medicom.

The factory has increased production to seven days week, three shifts per day, and is looking to hire 30% more staff. And that's not the only Medicom location to do so; its U.S. facility is moving to three shifts per day, too. "Our target right now is to protect as many people as we can," Laverdure said.

Masks are now hard to come by in the United States, as well.

The National Community Pharmacists Association on Thursday released results of a national survey that said 96% of local pharmacies are experiencing a shortage of surgical masks, and nearly 40% are don't have enough N95 respirators.

"All the masks that we restocked in the morning were gone by the afternoon," a salesperson at a Walgreens pharmacy located near the Hudson Yards of New York City told CNN Business.

Leading U.S. pharmacy chains, such as CVS and Walmart, show few to no medical masks or N95 respirators on their websites.

"We are working with our suppliers to meet customer demand for face masks," Amy Thibault, senior manager of communications at CVS Health, told CNN Business. "We will re-supply those stores [that are out of masks] as quickly as possible."

Given the shortages in China, some groups are trying to buy supplies in the United States and send them overseas. Wuhan University Alumni Association of Greater New York raised over $600,000 through a Gofundme campaign to send medical supplies to doctors and patients in the Wuhan area, including 40,000 masks bought from U.S. manufacturers.