The US Air Force’s “Doomsday Plane” arrived at Joint Base Andrews on Tuesday night, stoking rumors of a possible US engagement in the intensifying Israel-Iran conflict.

The E-4B Nightwatch aircraft landed at a military installation in suburban Washington, D.C., as speculation mounts over possible US military action in Iran.

The deployment of the E-4B coincides with heightened tensions as President Donald Trump is said to be getting closer to launching military attacks on Iran’s nuclear installations. While the White House has not commented on the aircraft’s recent relocation, social media users believe it indicates possible military preparation from the United States.

The E-4B “Nightwatch,” known as the “Doomsday Plane,” is a weaponized Boeing 747. It is the National Airborne Operations Center and an important part of the National Military Command System for the president, the secretary of defense, and the Joint Chiefs of Staff.

In the event of a national emergency or the loss of ground command, the aircraft “provides a highly survivable command, control, and communications center to direct U.S. forces, execute emergency war orders, and coordinate actions by civil authorities,” according to the US Air Force.

It was utilized during the 9/11 attacks.

The adoption of an unusual callsign—”ORDER01″ rather than the standard “ORDER6″—sparked conjecture regarding the nature of its present mission.

It’s unknown if the recent trip from Barksdale Air Force Base near Bossier City, Louisiana, to Joint Base Andrews was a normal operation or a precautionary measure, although Newsweek earlier reported that it was most likely just a show of force.

The E-4B Nightwatch is capable of being aloft for lengthy periods of time and refueling in the air. Protected against electromagnetic pulse assaults and capable of surviving a nuclear bomb, the plane is outfitted with modern satellite communications and shielding technology, and it can accommodate more than 100 passengers.

“In case of national emergency or destruction of ground command and control centers, the aircraft provides a highly survivable command, control, and communications center to direct U.S. forces, execute emergency war orders, and coordinate actions by civil authorities,” the U.S. Air Force said.

The aircraft’s landing coincided with news that Trump is considering taking military action against Iran’s nuclear facilities.

The Wall Street Journal claimed Wednesday that the president informally authorized operational assault preparations but did not authorize a strike.

President Trump denied the WSJ report on Thursday morning.

Meanwhile, Israel and Iran are trading air and missile attacks, raising already high regional tensions.

Senior sources informed many publications, including CNN, that Trump is less convinced by diplomatic alternatives and is becoming more open to military engagement.

President Trump told reporters on Wednesday: “I’m not looking to fight. But if it’s a choice between fighting and [Iran] having a nuclear weapon, you have to do what you have to do, and maybe we won’t have to fight.”

Ayatollah Ali Khamenei, Supreme Leader of Iran, said in a public address: “The Americans should know that any U.S. military intervention will undoubtedly be accompanied by irreparable damage. The U.S. entering in this matter is 100 percent to its own detriment. The damage it will suffer will be far greater than any harm that Iran may encounter.”

Several mysterious cargo planes from China have flown near Iran’s airspace before disappearing from radar, raising concerns that Beijing may be covertly supporting the conflict, according to reports.

Public flight trackers revealed at least three Boeing 747 freighters—often used to transport military equipment and weapons—departing from Chinese cities on Saturday (the day after Israel struck Iran), Sunday, and Monday.

Each plane flew west across northern China, crossed into Kazakhstan, then continued south through Uzbekistan and Turkmenistan before vanishing from radar near Iran.

Although the flight plans indicated Luxembourg as the destination, none of the aircraft seemed to head toward Europe.