Hawley didn't say when the program would be implemented.

Testifying before the committee, Catherine Berrick, the GAO's director, Homeland Security and Justice Issues, said that although Secure Flight has been in development for three years, the agency still faces significant challenges in developing and implementing the program.

For one thing, Berrick said, the TSA has not properly managed the development of the program, choosing to develop it quickly rather than accurately.

"As a result of this approach, the development process has been ad hoc, with project activities conducted out of sequence, requirements not being fully defined, and documentation containing contradictory information or omissions," Berrick said.

In addition, even though the TSA has taken steps to make sure that the Secure Flight system is secure, its efforts are incomplete, she said. The agency is also developing the program without defining system requirements and cost estimates, she added.