Nicknamed “the Bone”, the aircraft has advanced radar and GPS systems to help hit targets, and electronic jammers, radar warnings and a decoy system to protect it from enemies.
RAF Fairford, located on the border of Gloucestershire and Wiltshire, has been used by the US in the past to conduct long-range heavy bombing missions.
While the UK has given permission for the US to use British bases to conduct defensive strikes on the facilities, it has not taken part in the action itself.
RAF jets have been shooting down missiles and drones fired by Iran at allies in the region.
Earlier on Friday, the prime minister’s spokesman told reporters: “We’ve been very clear that our response has been to allow the US limited, specific and defensive use of our bases to protect British lives, British interests and our allies in the region.”
He added that the UK military was focused on shooting down drones in the air, while the US targets missile launch sites in Iran.
“We have consistently said that we’ll take the necessary steps to prevent future strikes which, as we’ve set out over the course of the week, is allowing the US to take out those missiles at source whilst we are defending the skies.”