One of America’s “doomsday planes” made a flight to Joint Base Andrews in Washington, DC, Tuesday night as President Trump weighs whether to strike Iran’s nuclear facilities.

The E-4B Nightwatch — which was designed to protect the secretary of defense and other national security officials and keep the government operating in a time of nuclear war — was spotted by flight trackers, and took a long, winding route to the capital.

The aircraft left Bossier City, Louisiana, just before 6 p.m. Tuesday and landed in Maryland at 10 p.m. after skirting the coast and looping around the border of Virginia and North Carolina, data from flight tracking site FlightRadar shows.

Confusion was sparked after the flight issued an unusual callsign, ORDER01, instead of the usual ORDER6, according to flight data.

The US fleet of four E-4Bs makes regular flights year-round to maintain military readiness.

The E-4B serves as an airborne command center for the president, secretary of defense, and the chairs of the Joint Chiefs of Staff to ensure continued critical command, control and communication in case of emergencies.

Each E-4B Nightwatch can carry a crew of up to 112 people and has a range of more than 7,000 miles.

Their importance to the US Air Force is demonstrated by the fact that they feature unique capabilities that cannot be copied by any other US Air Force aircraft.

They are capable of withstanding nuclear blasts, cyberattacks and electromagnetic effects, and are equipped to fire retaliatory missiles.

The aircraft also has thermal and nuclear shielding and can communicate with anyone anywhere in the world, thanks to the 67 satellite dishes and antennas contained in its ray dome.

They are designed to remain airborne for an entire week without needing to land and can refuel in midair.

The longest an E-4B has been known to stay in the air is 35.4 hours.

With 18 bunks, a briefing room, teamwork area, conference room, command room, and designated rest area spread across three decks, the aircraft is designed to be a “flying Pentagon” in the event of a national emergency.

President George W. Bush’s secretary of defense, Donald Rumsfeld, used the E-4B as his primary mode of transportation.

The mission may be linked to increased presidential security amid soaring tensions in the Middle East, some observers suggested.

The US Air Force is in the process of replacing its fleet of E-4B Nightwatch aircraft.

Last April, a $13 billion contract was signed with Sierra Nevada Corporation to develop a replacement for the aircraft, the Aviationist reported.

It comes as Trump demanded Iran’s “unconditional surrender” as the conflict between the Iranian regime and Israel intensified.

Iran’s supreme leader, Ayatollah Ali Khamenei, rejected Trump’s calls on Wednesday, despite the latest airstrikes on Tehran forcing thousands to flee the Iranian capital.

At least 224 people have been killed in Iran since Israel launched its bombing campaign on the Islamist regime last week.

Two Iranian governmental aircraft left the country’s airspace on Wednesday bound for Oman, FlightRadar data show.

This sparked speculation that senior Iranian leaders were either fleeing their besieged country, or that emergency peace talks were set to take place in the Omani capital, Muscat.