Beyond violating our laws, visa overstays, pose - and they really are a big problem, pose a substantial threat to national security.

We cannot allow a beachhead of terrorism to form inside America. We cannot allow our nation to become a sanctuary for extremists.

Within hours of taking the oath of office, I declared a national emergency on our southern border, and I deployed the US military and border patrol to repel the invasion of our country. And what a job they've done. As a result, illegal border crossings last month were by far the lowest ever recorded. Ever.

We're going to show great heart. DACA is a very, very difficult subjects, one of the most difficult. You have these incredible kids in many cases, not in all cases, in some of the cases they are gang members and drug dealers, too. But you have some absolutely incredible kids, I would say mostly. They were brought here in such a way, it's a very, very tough subject.

You have to end it now. I see it, I can tell you. I'm really good at this stuff. Your countries are going to hell. In America, we've taken bold action to swiftly shut down uncontrolled migration. Once we started detaining and deporting everyone who crossed the border and removing illegal aliens from the United States, they simply stopped coming. They're not coming anymore.

I will build a great wall-and nobody builds walls better than me, believe me-and I'll build them very inexpensively. I will build a great, great wall on our southern border, and I will make Mexico pay for that wall. Mark my words.