Pushing back on a letter from three U.S. senators, Atlanta-based Delta Air Lines said Thursday that it is not, and has not, used or are testing an artificial intelligence system for ticket pricing.

Delta Air Lines said on Friday it will not use artificial intelligence to set personalized ticket prices for passengers after facing sharp criticism from U.S. lawmakers and broad public concern. Last week,

"There is no fare product Delta has ever used, is testing or plans to use that targets customers with individualized prices based on personal data," Delta told senators in a letter on Friday.