A US defense official said there has been no order given to move forward with any kind of operation against Iran using the B-2s.

As of Saturday, the planes are flying over the Pacific and appear to be headed toward Guam.

Two US defense officials cautioned that any movement of B-2s does not mean an operation is imminent but rather is intended to provide the president with options.

Another US official said moving aircraft can be a show of force and a deterrent as Trump deliberates.

B-2 bombers are the only plane capable of carrying the Massive Ordinance Penetrator, which experts have highlighted as the only type of bomb potentially capable of destroying Iran’s underground Fordow nuclear facility.

Each B-2 bomber is able to carry two of these “bunker buster” bombs, which weigh an impressive 30,000 pounds (13607kg) each.

The movement of the B-2 bombers comes as Trump has spent much of the past week in the Situation Room, reviewing attack plans and quizzing officials about the potential consequences of each.

Trump is set to hold a meeting with his national security team in the Oval Office on Saturday and Sunday evening.

The White House didn’t respond to a request for comment.

On Friday night, eight US Air Force KC-135 Stratotankers took off from Altus, Oklahoma, according to data from FlightRadar24.

Over Kansas the tankers refueled two groups of planes, identified on air traffic control audio by their callsigns MYTEE11 FLT and MYTEE21 FLT.

The callsign MYTEE has previously been associated with special activity flights by B-2 bombers, and multiple flight trackers on social media said the planes being refueled were B-2 bombers out of Whiteman Air Force Base in Missouri.

Flight tracking data and air traffic control audio reviewed by CNN show the bombers refueled again off the coast of California, and over Hawaii.

Satellite imagery taken on Thursday showed six KC-135 refueling planes stationed at Diego Garcia, a remote island in the Indian Ocean that could be used to refuel the bombers should they continue onward to Iran.