An analysis of satellite images shows increased activity at North Korea 's nuclear site . It says it is ` ` " and bolster '' its nuclear program . It says it is acting in self - defense to ` ` the hostile policy of the U.S. '' Western governments have warned North Korea it faces further isolation over its nuclear program .
An analysis of satellite images shows increased activity at North Korea 's nuclear site . Pyongyang says it will `` expand and bolster '' its nuclear program . It says it is responding in self-defense to `` the hostile policy of the U.S. '' G8 leaders have warned North Korea it faces further isolation over its nuclear program .