American Airlines Group Inc said on Sunday it was waiving change fees on all newly purchased tickets amid declining air travel demand because of the new coronavirus outbreak.

The largest U.S. airline said it would waive change fees up to 14 days before travel for customers who purchase tickets between Sunday and March 16.

JetBlue Airways Corp said last week it would suspend change and cancellation fees for new flight bookings between Feb. 27 and March 11.

American Airlines shares have fallen 37% since Feb. 13.

United Airlines Chief Executive Oscar Munoz told employees the U.S. airline would likely need to cut additional flights in the wake of sagging demand because of the coronavirus outbreak, the airline confirmed on Sunday.

In an email late on Saturday to employees, Munoz noted the carrier had cut flights to Asia and suspended service to mainland China and Hong Kong through April 30.

"We are strategically managing our Atlantic and domestic service, mindful of travel directives from the federal government, fluctuating demand and of course, the advice of public health experts. Based on current trends, it is likely that additional schedule reductions will be necessary," Munoz said. The email was reported earlier by CNBC.

On Friday, United canceled its investor day that was set for March 5, saying it is not "practical to expect that it can have a productive conversation focused on its long-term strategy next week." It will reschedule for September.

Chicago-based United already withdrew its 2020 guidance last week because of the uncertainty over the duration and spread of the virus. It warned that near-term demand to China has almost disappeared, with demand for the rest of its trans-Pacific routes down by 75%.