Turkish Airlines will pause almost all international flights from March 27 until April 17.
The flag carrier said all routes except New York, Washington, Hong Kong, Moscow and Addis Ababa would be suspended.
Domestic flights will continue with reductions in frequency, and cargo flights will continue as normal.
The airline has waived all change fees for existing tickets for travel until the end of the year. These can be rebooked for a flight before February 28, 2021, though they can only be changed once, the new ticket must be to the same region as the original destination, and additional fares will apply. See the full policy here.
Change requests can be made through Turkish Airlines sales offices, its call centre, online channels and agencies from which the ticket was purchased.
However, like many airlines, it has asked people not to call its customer service agents unless they have an urgent query or flight within 72 hours.
Airlines around the world have announced huge capacity cuts for the coming months amid the coronavirus pandemic.