Anchor: North Korea's threats of "merciless" strikes against the U.S. and decision to move a mid-range missile to its east coast have pushed the U.S. to decide to deploy an advanced missile defense system to Guam. Our Kim In-kyung has the story.

Report: Pentagon officials said Wednesday the U.S. will deploy a ballistic missile defense system to Guam in the coming weeks to enhance its regional defense posture against the missile threat posed by North Korea.

North Korea stepped up its rhetoric Wednesday, saying it formally informs the White House and the Pentagon that it will smash hostile policies against the North with cutting-edge nuclear strike means. A spokesman for the North's military said it has received final approval for the "merciless operation" of its revolutionary forces against the U.S.

The U.S. Defense Department’s precautionary move also follows South Korean and U.S. intelligence reports that North Korea appears to have moved an intermediate-range missile to the east coast. The Musudan missile has a range of three- to four-thousand kilometers, which puts the U.S. military base in Guam within striking distance.

South Korean and U.S. intelligence officials are closely tracking the missile’s movements as they believe Pyongyang may fire the Musudan around April 15th to celebrate the birthday of North Korea’s founder Kim Il-sung.

The Pentagon said the Guam-bound Terminal High Altitude Area Defense System, or THAAD, is land-based and comprised of a truck-mounted launcher, interceptor missiles, and radar tracking equipment. The THAAD missile uses hit-to-kill technology, meaning it destroys enemy missiles by colliding with them.

Kim In-kyung, KBS World Radio News.