Boeing received a contract in 2009 to fit the weapon on the U.S.'s B-2 Stealth Bomber.

WSJ: Pentagon Seeks Mightier Bomb vs. Iran

The U.S. has said North Korea does not possess a nuclear warhead or the required technology to miniaturize one to fit on its rockets, but it could put a "dirty bomb" or conventional weapon on one.

CNN: Analysis: Amid pending launch, N. Korea only shows half its hand