He said it would improve screening efficiency and allow security to focus on items that pose more serious threats to aviation.

CNN: U.S. to keep restriction on small knives on planes for now

The TSA administrator is required to approve airport applications for the program if security is uncompromised, cost efficiency is maintained and the screening of passengers and property is not negatively impacted.

CNN: Florida airport pushing to opt out of TSA

But Pistole has been under pressure from congressional lawmakers, flight crews and others concerned the change dangerously relaxed aviation security and sent the wrong message to a flying public eager for more simplicity and efficiency in passenger and bag screening.

CNN: U.S. to keep restriction on small knives on planes for now