Transcript for North Korea Puts Pentagon on High Alert
North -- drumbeat of directives Metairie continued today with the new threat warning letters had been given to attack the United States with a nuclear weapon. With such threatening talk coming from the commander of the world's fourth largest military the Pentagon is on high alert. Some of the actions they've taken over the last few weeks. -- -- A real and clear danger. And threat. To the interest certainly. Of our allies view on the administration has been -- new weapons and -- the region. Two more warships stealth fighter jets and it's based missile interceptor has been sent to want to target any launches from the north. And today US troops practiced has -- zeros in case of a chemical weapons attack. With -- world's second largest stock -- The chemical weapons. But experts say an attack on the US would be a highly unlikely and bring their thirty year old leader Kim -- -- North Korea is obsessed with the military balance. They're very aware of military power. And when it's not in their favor. They can be deterred because they wished to survive. So attacking the US would be committing suicide. Caught in the middle of -- brinksmanship by the people of South Korea but on the streets of -- today. There's no sign of panic. Most people here are carrying on with life as usual. But anxiety. Is slowly building that you -- -- rhetoric may spin out of control. Ending up as more than just tall sure he Cho ABC news soon.
This transcript has been automatically generated and may not be 100% accurate.