The Pentagon has prepared a specific plan for a preemptive strike on North Korea’s missile sites should President Trump order such an attack.

Two senior military officials — and two senior retired officers — told NBC News that key to the plan would be a B-1B heavy bomber attack originating from Andersen Air Force Base in Guam.

Pairs of B-1s have conducted 11 practice runs of a similar mission since the end of May, the last taking place on Monday. The training has accelerated since May, according to officials. In an actual mission, the non-nuclear bombers would be supported by satellites and drones and surrounded by fighter jets as well as aerial refueling and electronic warfare planes.