Transcript for North Korea remains defiant after its failed missile launch over the weekend

The other major story tonight, the new threat from North Korea. The escalating war of words. North Korea now threatening missile tests every week. Vice president Mike pence visit the border, warning North Korea and reminding them about the U.S. Strike in Syria and the U.S. Bomb dropped in Afghanistan a week later. Or correspondent asking president trump, what's next. ABC's Martha Raddatz reporting from South Korea tonight. Reporter: Tonight, a defiant North Korea pledging to conduct missile tests on a weekly, monthly and yearly basis, accusing the white house of pushing the situation there to the brink of war. Thermonuclear war may break out at any moment on the peninsula. Reporter: But now from president trump -- a blunt warning. Any message for North Korea? You got to behave. Reporter: In Pyongyang this weekend Kim Jong un's military might on full display, including what appeared to be a new long-range ballistic missile, canisters of green camo mounted on huge transporters, but amid that show of force, an embarrassing failure -- a botched missile test, the weapon exploding seconds after launch, and tonight, questions about whether it was cyber-sabotaged by the U.S. There is a very strong belief that the U.S., through cyber methods, has been successful on several occasions in interrupting these sorts of tests and making them fail. Reporter: Tensions between the U.S. And North Korea now at an all-time dangerous high. North Korea is a problem. The problem will be taken care of. Reporter: But just what that means, unclear. The era of strategic patience is over. Reporter: In South Korea vice president pence visiting the dmz, delivering a warning of his own. Just in the past few the world witnessed the resolve and the strength of the united States. Reporter: Nearly 30,000 American troops are currently stationed in South Korea. We visited one key base just 48 miles from the border. Here, they are at the ready. Their slogan -- fight tonight. There aren't many places I go into where it says "Fight tonight" in giant letters. Absolutely. Reporter: That's a little frightening. Absolutely. But for us it's our day-to-day training because we don't know when that call is going to come. Reporter: As for the commander- in-chief, the white house says he's holding his cards close to the vest. I don't think that you're going to see the president drawing red lines in the sand. Reporter: Today when asked his next move, president trump with just a two-word answer -- you'll see. So let's get to our chief global affairs correspondent Martha Raddatz joining us. Martha, we heard the vice president saying, the world witnessed the strength of our new president in the actions taken in Syria and a week later in Afghanistan. People wondering tonight, is North Korea next? Reporter: Well, that is a message he wants North Korea to hear but also China, the vice president said he and president trump have great confidence in China but if they don't pressure North Korea in a meaningful way, the U.S. And its allies will. David. You heard the president today, make no mistake he's not revealing anything here. He's not going to tell anybody what he's doing next, David. Martha Raddatz reporting from South Korea. I want to get to Steven ganyard. First this new threat from north Korea tonight, the threat to carry out weekly tests, could they pull this off. They test for two reasons to develop new missiles and they also want to stay on the stage. Once a week is not unreasonable. The world was watching, though, over the weekend for any possible nuclear tests, how real is that part of that threat? It's very real. They have been using satellite imagery to look at this mountainous region. They declared it primeded and ready to go. The next step is all up next to Kim. He All right, colonel ganyard with us. Next tonight, the white house responding to protests

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