The United States will send 24 B-1 and B-52 bombers to Guam in the Pacific to deter any aggression by North Korea in case of a war in Iraq, defence officials said on Tuesday.

The deployment order is to maintain peace and not prompted by the interception of an unarmed US reconnaissance jet by North Korean fighters in international air space over the Sea of Japan on Sunday, the US officials said.

The Pentagon issued this statement in connection with the move:

"As part of our global efforts to address worldwide requirements, we are deploying additional forces to the Western Pacific as US forces are preparing for possible military action elsewhere in the world. These moves are not aggressive in nature. Deploying these additional forces is a prudent measure to bolster our defensive posture and as a deterrent. As the President has said, we are seeking a peaceful, diplomatic resolution of the international community's concerns over North Korea's nuclear weapons program."

In Sunday's incident, four North Korean MiGs intercepted the RC-135 surveillance plane about 240km off the North Korean coast.

The Pentagon said at one point one of the fighters 'locked on' to the US plane with its fire-support radar, an action that indicates intent to fire.