Delta Air Lines and American Airlines cancelled flights to and from Haiti following a 7.0 magnitude earthquake on Tuesday that may have killed thousands of people.

Delta cancelled its flight from New York's John F Kennedy Airport to Port-au-Prince, Haiti's capital, company spokesman Anthony Black, said on Wednesday.

American Airlines flew its last flight from Haiti to Miami on Tuesday night around 6:45 pm, spokesman Tim Smith said.

Both carriers said they were uncertain when flights to Haiti would resume.

The earthquake's epicentre was 10 miles from Port-au-Prince. Aftershocks as powerful as 5.9 rattled the city on Tuesday night and Wednesday. About 4 million people live in the city and the surrounding area.

JetBlue Airways said it would waive change fees and fare differences to allow customers to rebook their travel to the Dominican Republic.

The US State Department urged Americans not to travel to Haiti.