Tonight there's urgent new evidence that north korea is ready to launch a missile at any hour, any moment, a show of force, a defiant test of world reaction. Abc news has been told that the fuel has... See More
Tonight there's urgent new evidence that north korea is ready to launch a missile at any hour, any moment, a show of force, a defiant test of world reaction. Abc news has been told that the fuel has been loaded. The missile is on the pad. And our bob woodruff is in south korea to bring us more details right now. Reporter: The top u.S. Defense official responded to kim jong-un'sising rhetoric today. North korea's actions have been skating very close to a dangerous line. Reporter: There is some anxiety growing on the streets and in the subways of seoul amid south korean news reports than emergency threat levels jumped to watchcon-2, which is one step away from war. Even as koreans went about their daily routines, young koreans have lived through endless propaganda and missile tests for decades. Now even they are starting to wonder about kim jong-un. He is very crazy. Reporter: He's crazy? Parents are getting nervous. Sae jung kim told me for the first time in this conflict tomorrow, she will not take her son to kindergarten. Any strike, anywhere else, i want my kids to be with me. Reporter: Even if that happens, that missile would be mid range called muse dan. Never before tested. Powerful enough to travel 2,000 miles putting u.S bases in okinawa or guam within its reach. Moving patriots missiles into position around tokyo. The danger here is kim jong-un has ramped up the tension to such a point that even the smallest ackedz could provoke a larger fight, a war or significant military clash. Reporter: As for timing, most believe this launch will happen sometime this week because next monday is kim jong-un's grandfather's birthday. On that day, most of these launches have happened in the morning. So we will see very soon.
This transcript has been automatically generated and may not be 100% accurate.