North Korea vows to block border with South Korea and build front-line defense structures

To cope with 'confrontational hysteria' by U.S. and South Korean forces, North Korea said it will block its border with South Korea permanently and will cut off railways and roads to the country.

While the moves were likely a pressure tactic, it's unclear how they will affect ties with South Korea since cross-border travel and exchanges have been halted for years.

North Korea's military said it will "completely cut off roads and railways " linked to South Korea and "fortify the relevant areas of our side with strong defense structures," according to the North's official Korean Central News Agency.

The North's military called its steps a "self-defensive measure for inhibiting war and defending the security" of North Korea. It said that "the hostile forces are getting ever more reckless in their confrontational hysteria." It cited what it called various war exercises in South Korea, the deployment of U.S. strategic assets and its rivals' harsh rhetoric.