The operation, set to take place in June, will prepare for the safe exit of around 230,000 Americans in the case of conflict.

If the Pyongyang was to attack, tens of thousands of American civilians, including military dependents residing in and around the capital city of Seoul, could very well be caught in the crossfire.

A major dilemma for the US is how to keep these Americans safe and evacuate them in the event of hostilities.

Seoul is just 35 miles from the border, well within range of more than 12,000 North Korean artillery guns that they have already positioned to strike from dug-in and well-camouflaged positions.

According to reports, the reclusive state would activate sleeper agents in the South to direct missile and artillery fire.

It is estimated that the North has the capability to fire, using rocket-assisted projectiles, 500,000 rounds of both mortar ammunition and chemical weapons on Seoul in just the first hour of war.