Ahead of President Biden's visit to South Korea and Japan, the U.S. military aircraft nicknamed the "Doomsday plane" has been spotted flying above Japan.
A move seen as being aimed at North Korea's apparent preparations for an ICBM launch or nuclear test.
The U.S. Air Force's command and control military aircraft, the "E-4B", acts as a flying office for the secretary of defense, in case of a dire security situation such as a natural disaster or nuclear war.
It's built to withstand a nuclear attack and to allow the federal government to continue to operate from the air.
Pentagon chief Lloyd Austin also used this aircraft when visiting Seoul last December for a meeting with the South Korea's defense minister.