ATLANTA, United States (REUTERS) - Delta cancelled about 800 flights in or out of Atlanta on Monday (Sept 11).

The cancellation is due to the Tropical Storm Irma, which is bearing down on Atlanta, Georgia. The number two US airline said it is bringing strong crosswinds that could make landing dangerous.

Travel industry analyst and advisor of Atmosphere Research Group Henry Harteveld says: "It's a standard procedure. When the winds get above a certain speed, and it will vary for the airport in that type of airplane, it becomes unsafe to operate. So, the airports will close, and the airlines won't fly there. It's a common sense decision."

Atlanta is Delta's main traffic hub. The airline's headquarters are also based in the city.

At the same time, Delta is working on resuming service to airports in Florida that got hit by Irma.

Its bigger rival - American Airlines - said on Sunday (Sept 10) it would not resume commercial flights to Miami on Monday but may operate flights to bring in staff and supplies.