TSA begins testing 'known-traveler' program at four airports

"This new screening system holds great potential to strengthen security while significantly enhancing the travel experience whenever possible for passengers,” he continued.

While it is in its pilot stage, TSA said the PreCheck program would be available to passengers on Delta and American airlines.

The program will be tested through a partnership with Customs and Border Protection.

TSA has been harshly criticized by lawmakers in Congress, especially Republicans, for its current airport security procedures, which include controversial hand-searches known as pat-downs and full-body X-ray scanners.