It would be unwise to say the least, irresponsible of us at the TSA, at the Homeland Security Department not to evolve our technology to match the changing threat environment that we inhabit.

Let me be very clear: We monitor the risks of violent extremism taking root here in the United States. We don't have the luxury of focusing our efforts on one group; we must protect the country from terrorism whether foreign or homegrown, and regardless of the ideology that motivates its violence.

Each and every one of the security measures we implement serves an important goal: providing safe and efficient air travel for the millions of people who rely on our aviation system every day.

As part of our layered approach, we have expedited the deployment of new Advanced Imaging Technology (AIT) units to help detect concealed metallic and non-metallic threats on passengers. These machines are now in use at airports nationwide, and the vast majority of travelers say they prefer this technology to alternative screening measures.

Well, you know, I think in conversations with members of the Senate and others, they all recognize that the issue of immigration is important. It's important to our nation, it's important to our public safety, it's important to our security, it's important to our economic well-being moving forward. And it's not something that's going to go away.

So not only do we need to deal with threats as they emerge, we have to be thinking in anticipation of future threats, and the things we do have to be things that enable the system to continue to work.

Now, a lot of what we are doing right now, quite frankly, is because of what happened on Christmas. Many of the things were kind of in the works. We were already planning, for example, the purchase and deployment of advanced imaging technology. You call them body scanners. We call them AITs (Advanced Imaging Technologies).