Homeland Security Secretary Gen. Jack Kelly discusses border security with NBC's "Meet the Press." (Screen grab from NBC)

(CNSNews.com) - “The laws on the books are pretty straightforward. If you’re here illegally, you should leave or you should be deported,” Homeland Security Secretary John Kelly told NBC’s “Meet the Press” in an interview that aired on Sunday.

But Kelly said it’s not as easy as it sounds, and he said it’s up to Congress to fix the “complicated” problem of what to do with the 11 million illegal aliens estimated to be in this country:

“There are people who came here as children. There are people here who came here illegally many years ago and have married local men and women and had children. It's a very complicated problem.”

Kelly said just being in the United States illegally doesn't necessarily get you targeted for deportation. “It's got to be something else,” he said. “And we're operating more or less at the other end of the spectrum, and that is criminals, multiple convictions.”

Kelly agreed that the Trump administration is more likely than the Obama administration was to deport people for breaking the law, even jus once.

For example, he said that someone “with multiple DUIs, even a single DUI…would get you into the system,” meaning that such a person could be flagged for deportation.

“But you've got to remember that there's a system, a legal justice system in place. And the law deports people. Secretary Kelly doesn't. ICE doesn't. It's the United States, you know, criminal justice system, or justice system that deports people.”

He added that “there’s a lot of people out there that need to be taken into custody and deported, according to the law.”

He also said people who overstay their visas comprise “quite a large number of the illegals that are in the country.”

He said it’s “time-consuming” to round up visa overstays, because they have to be tracked down, then put in deportation proceedings.