The main architect of a 1994 pact between the United States and North Korea to end Pyongyang's nuclear arms program said Tuesday the U.S. feared a decade ago that Japan and South Korea might seek atomic weapons.

Robert Gallucci also said the U.S. was concerned that such moves by Japan and South Korea to acquire nuclear arsenals would adversely affect negotiations to make the Nuclear Nonproliferation Treaty permanent and trigger proliferation in other parts of the world.

"The situation of a serious North Korean nuclear weapons program could ultimately lead to the destruction of the norm of the international nonproliferation regime, and we worried about that being the consequence, that being the domino effect," Gallucci, who was a State Department official at the time, told a meeting held by the Nuclear Policy Research Institute.

In the nuclear crisis a decade ago, the administration of President Bill Clinton was considering bombing the Yongbyon nuclear complex as one option.