WASHINGTON (REUTERS) - New rules took effect just before midnight on Tuesday (Feb 2) requiring millions of travellers in the United States to wear masks on airplanes, trains, buses, ferries, taxis and ride-share vehicles and in airports, stations, ports and other transit hubs.

The new rules were ordered by the US Centres for Disease Control and Prevention (CDC) last Friday to address the spread of Covid-19 after being blocked by President Donald Trump from imposing the requirements in August.

President Joe Biden signed an executive order on Jan 21 tasking federal agencies with issuing rules "to save lives and allow all Americans, including the millions of people employed in the transportation industry, to travel and work safely."

Advocacy group FlyersRights.org on Monday urged the Biden administration to go farther and mandate the use of N95, KN95 or surgical masks on airplanes as well as "stricter social distancing guidelines, temperature checks (and) rapid testing." The CDC order allows homemade masks.

The Transportation Security Administration (TSA) issued security directives on Sunday allowing them to issue civil penalties and deny access to flights to travellers not wearing masks. The rules will be in effect through at least May 11.

Travellers are permitted for brief periods to remove masks for eating, drinking, or taking medications but masks "must be worn between bites and sips," TSA said.

Nearly all US travel is covered by the rules, but people in private cars and solo truck drivers are exempt.

The order requires all passengers two and older to wear masks but travellers can avoid wearing masks if they have a disability.

American Airlines said customers with disabilities unable to wear a mask must notify the airline 72 hours prior to departure to request an exemption and show proof of a negative Covid-19 test taken within three days of departure or proof of recovery to board.

US airlines have banned thousands of people from future flights for failing to wear masks. Delta Air Lines Chief Executive Ed Bastian said on Monday the airline had banned about 950 people to date.

He said Mr Biden's order "adds a layer of protection for our people who have been integral in enforcing our mask policy."

TSA said air carriers must make "best efforts to disembark the person who refuses to comply as soon as practicable."