U.S. airline passengers who refuse to wear a face mask could be banned permanently.

The Airlines for America Group recently announced that it intends to get stricter with enforcing face masks on planes.

Delta Air Lines issued a statement to passengers about the importance of wearing face masks to reduce the spread of the coronavirus.

“Those who choose not to comply with this or other safety requirements risk future flight privileges with Delta, which is in keeping with the face-covering enforcement policies Airlines for America recently announced,” Delta said.

Delta did not describe how the process would work in the statement.

United Airlines issued a separate statement announcing that anyone refusing to wear a face mask starting June 18 could be placed on a restricted travel list.

This is how United’s process will work: 

Flight attendants will inform passengers of the mandatory mask requirements if you’re not wearing a face covering, and you do not fall within a small group of exceptions.

If you don’t have a face covering, United flight attendants will offer you one.

Flight attendants will “do their best to de-escalate the situation and inform the customer [again] of the airline’s policy.”

United’s policy does not include forcibly removing a passenger who still refuses to comply, but the attendants will file an incident report, as reported in CNN.

The airline says that “any final decision or actions regarding a customer’s future flight benefits will not occur onboard but instead take place after the flight has reached its destination, and the security team has investigated the incident.”

What About The Other Carriers?

It’s important to note that the six other major US airlines all have separate policies when it comes to enforcing face masks policies.

“Each carrier will determine the appropriate consequences for passengers who are found to be in noncompliance of the airline’s face covering policy up to and including suspension of flying privileges on that airline,” a spokesperson for Airlines for America told CNN.