Airlines around the United States have updated their existing mask requirements to meet the new mandatory changes incorporated as part of an executive order issued by President Joe Biden.

Starting Tuesday, the Centers for Disease Control and Prevention (CDC) and the Transportation Security Administration (TSA) have issued orders to mandate masks during travel on public transportation, including aircraft and airports.

All airline passengers in the U.S. are now required to wear masks for the duration of their journey, while children under the age of two will continue to be exempt from the mask requirement.

“Our mask requirement has been and will continue to be a critical component of our comprehensive effort to protect the health and well-being of our customers and team members during the pandemic,” American Airlines Chief Operating Officer David Seymour said.

“This federal mandate will provide additional support to our crew members who are working diligently to enforce our policy and further reinforce the safety of air travel during COVID-19,” Seymour continued.

Travelers should be aware that bandanas and gaiters are no longer acceptable forms of facial coverings. Passengers who refuse to wear a mask may be denied boarding, removed from the aircraft or subject to penalties under federal law.

Airline customers with disabilities that inhibit their ability to wear a mask must notify their carrier at least 72 hours before departure to request an exemption. To be eligible, travelers must show documentation from a licensed health care provider and a negative COVID-19 test taken within three calendar days of departure.