Defense Secretary Chuck Hagel will announce Friday that the U.S. is deploying 14 new ground-based missile interceptors, probably in Alaska, defense officials told NBC News.
The officials didn't say specifically why the missiles are being deployed, but the announcement comes as North Korea has been making bellicose threats to void the armistice that ended the Korean War and launch a nuclear attack on the U.S.
The U.S. and South Korea began annual military drills this week despite the North Korean threats.