North Korea says it will permanently block its border with South Korea and build up front line defense structures to cope with what it calls confrontational histeria by south Korea and US forces. While the moves are likely pressure tactic, it's unclear how they will affect ties with the South since cross border travel and exchanges have been haulted for years. North Korea's military says it will completely cut off roads and railways linked to the South and fortify the relavant areas of our side with strong defenses.