Transcript for Trump offers vague threat against North Korea

This is president trump's fourth test from mother nature in two months. It is North Korea that has been on the president's mind this weekend with more ominous words directed at Kim Jong-un, North Korea releasing pictures of their leader overnight. ABC's Cecilia Vega is at the white house. Good morning, Cecilia. Reporter: Good morning to you, my friend. Good to see you there in new York. Ominous words as you say yet again and despite all of these attempts to get the president to clarify exactly what he means it seems president trump wants to keep the world in suspense. Another day, another vague threat against North Korea from president trump. This one as he was leaving the white house headed for an overnight fund-raiser in north Carolina. Asked what the one thing is that will work with Pyongyang -- Well, you'll figure that out pretty soon. Reporter: A tweet earlier in the day not offering much clarification. The president writing, presidents and their administrations have been talking to North Korea for 25 years. Agreements made and massive amounts of money paid hasn't worked. Agreements violated before the ink was dry making fools of U.S. Negotiators. Sorry, but only one thing will work. It follows last week's ominous message delivered while surrounded by his top military leaders. Maybe it's the calm before the storm. What storm, Mr. President? You'll find out. Reporter: And since then he's refused to explain. We pushed. Mr. President, what did you mean by calm before the storm yesterday? What did you mean by that. Thank you very much. Reporter: Only to be met with a wink. You'll find out. Reporter: Reporters tried again. Clarify your calm before the storm comment. Nothing, nothing to clarify. Reporter: But the president did say he has confidence in his secretary of state, despite a report that Rex tillerson called his boss a moron and threatened to resign. Very good relationship. I have a very -- that was fake news. Reporter: But that's not all. After the president what issued tillerson saying he was wasting his time trying to negotiate with Kim Jong-un, now this. We disagree on a couple of things, sometimes I'd like him to be a little bit tougher, but other than that we have a very good relationship. Reporter: So some tough words. As for his chief of staff president trump says has nothing but praise for general John Kelly despite reports out there that Kelly has grown frustrated with his job at the white house. The president says he's doing an incredible job and says he expects him to be in this position for the remainder of his, he says, seven years in the white house. He calls him one of the best people he's ever worked with. Seven year, huh? Cecilia, I've got to ask you, more tweet, a lot of tweets this weekend. This one caught my eye about chuck Schumer. He said I called chuck Schumer yesterday to see if the DEMs want to get a great health care bill. Obamacare is badly broken. Big premiums. Who knows. He called chuck Schumer and admitted he placed the call. What is going on. He called him Friday. Again he likes to call them chuck and Nancy. Remember when both the leaders were at the white house not too long ago. The president wants to cut a temporary deal, a one or two-year deal on health care basically Schumer said no dice. The president wants repeal and replace. He can't get that in his own party and Jon, as you know, Democrats say that is a N nonstarter for them too but, Jon, I got to take one issue with you there in New York, I'm loving this but I thought that we agreed you were going to come to me and call me like living legend, kind of beef up the team. Award winning, award winning senior white house correspondent. The one and only. Tremendous. Paula, you let me know if you need any -- I'm going to say, I don't know what we owe this pleasure of having you join us on the weekend but we're ternally grateful and indebted for your service. Thank you, your highness. The honorable Cecilia Vega. Honestly love having Cecilia on the weekends. We want to move on. We should do more of it. Another leading lady we have at ABC, Martha Raddatz, our chief global affairs gearing up to host "This week" later on this morning. Martha, love to have you on the show. Glad you're hosting this weekend. Following a living legend. How do you follow that? So, let's begin with -- It's tough. Let's talk about North Korea. Let's try to transition. You know, the president saying only one thing will work and when pressed about it says you'll figure it out pretty soon. How are we supposed to interpret it? Are we going to war? I think what you saw the other day in that photograph and him talking and talking the talk was very much off the cuff. I think there is nothing imminent planned, of course, unless North Korea does something extremely stupid. But it is that coercive diplomacy, the way it's been described to me, they are still trying to stay on a diplomatic track, the sanctions, they hope, work. But Donald Trump is going to keep up that chorus of, hey, if you don't do that, there could be military force. That is very Donald Trump. What you saw there in that photograph surrounded by the military and I think it was just off the cuff saying what -- the kinds of things he usually says with a wink added in to Cecilia. I'll tell you, ton of his senior advisers had any idea he was going to say that. That surprised them as much as it surprised all of us but what about John Kelly. There's been rampant speculation about his chief of staff. How long will he stay. We heard him say he'll be there for seven years. What are you hearing? Well, I don't know about seven years there, Jon and Paula but I think this is an extremely challenging job for John Kelly and he has had some very challenging jobs. This is a person who is disciplined, this is a person who is used to discipline. This is a person who is used to giving orders and having those orders followed. But I think John Kelly is there to stay as long as he feels he is serving the nation, because his background is a military officer, as a senior officer he does not throw in the towel. Despite frustrations, despite all of that and the same with general Mattis, secretary Mattis now, you have this background of serving the nation, I think both of them feel they will continue to do that as long as they feel they are helping the nation. It's that overwhelming sense of duty usurps everything else. Martha, have a great show. We'll let you go because we know you are preparing. She has two congressmen on Iraq war veterans with opposing views on gun control with a rare conversation on how congress should respond to the Las Vegas shooting and latest on Nate with the director of FEMA. What he says about what's going on in Puerto Rico. Coming up on "This week."

This transcript has been automatically generated and may not be 100% accurate.