The U.S. Centers for Disease Control and Prevention (CDC) late on Thursday said some 98% of the U.S. population live in locations where COVID-19 levels are low enough that people do not need to wear masks indoors.

The CDC on Feb. 25 dramatically eased its COVID-19 guidelines for when Americans should wear masks indoors, saying they could drop them in counties experiencing what it described as low or medium COVID-19 levels.

Last month, the CDC initially said 70% of counties covering 72% of Americans could drop masks. The latest update says 98% of Americans who live in 94% of U.S. counties can ditch masks.

The revised figures may give ammunition to critics who want the administration to lift mask requirements on airplanes, trains and in transit hubs.

The Biden administration earlier on Thursday said at the CDC's recommendation that it had agreed to extend requirements for travelers to wear masks on airplanes, trains and in transit hubs through April 18.

The decision extends by a month mask requirements that were set to expire on March 18.

The CDC said it will work with other government agencies "to help inform a revised policy framework for when, and under what circumstances, masks should be required in the public transportation corridor."

Just last week, the agency said 85.4% of counties covering 93% of the population were deemed to have low or medium COVID-19 levels and could skip masks. The latest figures are a sign of another dramatic fall in coronavirus infections.

U.S. government agencies have dropped mask requirements in federal buildings in the Washington area and other places with low or medium levels of COVID-19.