Donald Trump reacts to the terror attack in Nice, France, saying the United States is "weakly led." Trump said he will make it "very, very hard" for people to come into the U.S. from terrorist areas. Trump said he "would be so extreme in terms of documentation" and promised "extreme vetting." <a href="https://twitter.com/realDonaldTrump/status/753728269019549696">Trump tweeted</a> he would postpone tomorrow's announcement of his choice for vice president, Gov. Mike Pence. "I would be so extreme in terms of documentation," Trump told FOX News' Greta van Susteren on Thursday. "I would not allow people to come in from terrorist nations. I would do extreme vetting. I would call it extreme vetting, too. And, you know, our country has tremendous problems. We don't need any more of the problems." "What are we doing?" Trump asked. "We're trying to be so nice and so civil. We're so weak. The world has gotten to straighten up. We have to be very tight with our borders. It's now a different world, Greta. This isn't 40 years ago and 80 years ago. This is a different world. We're trying to be so politically correct. And we're making such big mistakes." <blockquote>VAN SUSTEREN: Donald, very disturbing news out of Nice, France right now. We’re still getting more information. Dozens killed, someone in a truck drove into a crowd. It’s Bastille Day, we’re hearing it’s total panic, locals are told to stay indoors, they don’t know what’s going on but it looks like it’s possible that this is terrorism striking Nice. Your thoughts? TRUMP: Well, it sounds like, here we go again. It’s going to be a whole different world. We’re living in a whole different world, that there’s no respect for law and order, there’s no respect for anything or anybody and this has to be dealt with very harshly and when I come out with my non-politically correct statements that a lot of people love and some people think are so terrible and then you have attacks like this and so many other attacks. I mean, let’s see what happens with this one. It’s early to tell but I would think perhaps you’re not wrong the way you started this question. We have to get awfully tough and we have to get very, very smart and vigilant and if we don’t, we’re just not going to have a society, we’re not going to have a world anymore. This is crazy what’s going on. VAN SUSTEREN: I don’t want to jump too far ahead, this is so early in the investigation but it has all the hallmark of terrorism. We saw that last November 13th in Paris and we have seen it in many other instances so naturally we all jump to the conclusion it’s terrorism. Assuming this is terrorism and assuming you were president of the United States, what would you be doing right now? TRUMP: Well, I’d be making it very, very hard for people to come into our country, for one thing, from terrorist areas. I would be so extreme in terms of documentation. We have people that Hillary Clinton wants to allow 550 percent more than Obama and Obama is allowing a lot of people to come in and we have no idea who they are. They are from Syria maybe but they have no paperwork, many times they don’t have documentation proper. I would make it -- I would not allow people to come in from terrorist nations. I would do extreme vetting -- I would call it extreme vetting, too -- and, you know, our country has tremendous problems. We don’t need any more of the problems. Right now we have more investigations of this kind going on than we’ve ever had in the history of our country and we’re going to allow thousands and tens of thousands of more people coming in and then you see a situation like in Nice, France. It’s a horrible thing and we better get awfully tough and I’m only -- I’m talking about our country but I’m almost talking about the world because look at what’s going on in France, look at what’s going on in other countries. It’s bedlam.</blockquote> Trump announces postponement: <blockquote class="twitter-tweet" data-lang="en"><p lang="en" dir="ltr">In light of the horrible attack in Nice, France, I have postponed tomorrow's news conference concerning my Vice Presidential announcement.</p>— Donald J. Trump (@realDonaldTrump) <a href="https://twitter.com/realDonaldTrump/status/753728269019549696">July 14, 2016</a></blockquote> <script async src="//platform.twitter.com/widgets.js" charset="utf-8"></script>