The US Centers for Disease Control and Prevention (CDC) on Friday urged Americans to start wearing N95 or KN95 masks used by healthcare workers and frontline workers in light of the growing COVID-19 cases in the country, driven by the highly transmissible omicron variant.

The updated CDC guidelines on masks say that Americans “may choose” to wear N95 and KN95 masks, but do not say that Americans should wear them.

Also read | COVIDTests.gov: White House announces website to order free COVID home tests

The CDC had earlier not issued any recommendations on what types of masks to wear, fearing that a spike in consumer demand would lead to a shortage of N95 and KN95 masks for healthcare workers. However, in the updated guidelines, it has removed this particular concern.

In the updated guidelines, the Centre clarified “that people can choose respirators such as N95s and KN95s, including removing concerns related to supply shortages for N95s.”

The latest CDC guidance notes that there is a special category of “surgical N95″ masks, that are specially designed for protection against blood splashes and other operating room hazards. Those are not generally available for sale to the public, and should continue to be reserved for health care workers, the agency said.

However, agency officials noted some masks are harder to tolerate than others, and urged people to choose good-fitting masks that they will wear consistently.

Also read | Differences between omicron and Delta: All you need to know

“Our main message continues to be that any mask is better than no mask,” Kristen Nordlund, a CDC spokeswoman, said in a statement.

The CDC’s updated guidelines were released on the back on President Joe Biden’s announcement on Thursday that his administration was looking to provide “high-quality masks,” including N95s, for free. The White House has also said that it has a stockpile of 750 million N95 masks in stock.

[With AP inputs]