Uncomfortable and "invasive" airport security pat-downs are here to stay, the top U.S. transportation security official said Sunday.

The Transportation Security Administration has triggered a public outcry with wider use of graphic full-body scanners, or full-body pat-downs for those who decline the scans or who require secondary screening. The security measures come in response to the attempted airline bombing last Christmas, when a Nigerian passenger allegedly hid a bomb in his underwear and failed to detonate it properly....