Transcript for Trump threatens Mexico: 'We will close' the whole US border

And on this Thanksgiving day, president trump is talking tough about the border. At mar-a-lago today, issuing an unprecedented threat to shut down the whole border if Mexico loses control of the migrants arriving there. The president also saying he has authorized troops on this side of the border to use deadly force. ABC's white house correspondent Tara Palmeri is in Florida tonight. Special people, very, very special people and we're very proud of you. Reporter: Shortly after making Thanksgiving calls to military leaders, president trump issued this striking drastic threat to Mexico. We will close entry into the country for a period of time until we can get it under control. For the entire border? The whole border. I mean the whole border. Reporter: The president not just threating immigration, but even saying he'll stop billions of dollars in trade. Mexico will not be able to sell their cars into the united States where they make so many cars, at great benefit to them. Not a great benefit to us, by the way. Reporter: Today, trump also intensified his feud with chief justice John Roberts, over a 9th circuit court judge's decision to temporarily block his asylum ban, tweeting, "Justice Roberts can say what he wants, but the 9th circuit is a complete and total disaster. Judges must not legislate security and safety at the border or anywhere else." It's the 9th circuit. Everybody knows it. It's totally out of control. Reporter: Earlier in the week, Roberts had make a rare rebuke of the president's take on the court, saying "That independent judiciary is something we should all be thankful for." What they're doing, what they're saying, the opinions are very unfair to law enforcement. Reporter: Today, the president also threatened to shut down the government if he doesn't get money for border security, including the wall. And he is now raising the possibility of deadly military confrontations with troops recently deployed on the border. If they have to, they're going to use lethal force. Did you authorize it? I've given the okay. I hope they don't have to, but you're dealing with a minimum of 500 serious criminals. Reporter: President trump took questions on a wide range of issues, but the final question was what he was most thankful for this Thanksgiving. For having a great family and for having made a tremendous difference in this country. I made a tremendous difference in the country. This country is so much stronger now than it was when I took office that you wouldn't believe it. Tara Palmeri in west palm beach with the president. And Tara, president trump was also asked about murdered "Washington post" reporter Jamal khashoggi and the CIA report that Saudi Arabia's crown prince may have ordered the killing. Once again, the president casting doubt on his involvement? Reporter: Whit, president trump is again defending Saudi Arabia. He's calling the conclusive, and saying that the crown prince vehemently denies his involvement. He also touted the economic benefits of maintaining ties with Saudi Arabia, claiming that if we cult ties with the country, the U.S. Will lose oil deals and oil prices would rise. Whit? Tara, thank you. And we heard from former FBI

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