Delta Air Line’s CEO Ed Bastian told NBC News’ host Willie Geist during an interview on the TODAY Show that flying on his airline during the COVID-19 era was a “really positive” experience.

“I know there’s a lot of anxiety in the general public and even for road warriors who have been out flying for years. We have space on our planes, we only book our planes to 60 percent full.”

Bastian said that some of Delta’s fliers have reported a “better experience” than they had flying before the Covid-19 pandemic.

The CEO remarks come as the airline’s tougher policy on mask-wearing takes effect. Fliers who cannot wear masks for medical reasons must submit to phone consultation with STAT-MD to verify the condition.

Otherwise, Bastian reiterated, “You cannot board a Delta plane unless you have a mask on.” In the absence of a verified medical reason, Bastian said, “If you board the plane and you insist on not wearing your mask, we will insist that you don’t fly Delta into the future.” Bastian warned travelers that “We already have over 100 people we’ve put on that list.”

Delta has got high marks among officials and many travelers for its move to continue blocking middle seats until after September and perhaps even longer. Other airlines including American Airlines and United have started booking full flights, albeit with caveats to notify fliers ahead of time by messaging that their flights were full, giving them an opportunity to rebook.

Delta has also publicly discussed its pivot toward a smaller, more customer-focused experience.

Bastian told TODAY, “We need the demand to come back, so I don’t know if government assistance is the answer. What we really need is a vaccine, we need some medical confidence back in consumers, and we need to continue to restore confidence in air travel.”