The US Air Force is investigating an incident of an intruder gaining access to the military facility that houses Air Force One.

A spokesperson for Joint Base Andrews in Maryland confirmed to the Air Force Times that the incident was under investigation, adding: “An unauthorised individual gained access to Joint Base Andrews.”

The probe is being handled by the Air Force Office of Special Investigations (OSI), with its spokeswoman Linda Card confirming to the Air Force Times that someone who gained access to the base is being interviewed by investigators.

The agency had no further details about the incident, including how far the intruder got onto the base or if they reached any aircrafts before they were caught.

President Joe Biden is scheduled to travel on Air Force One from the base on Friday evening for a journey to Delaware. It is located around 14 miles from Washington, DC.

The journey will be the first time Mr Biden has travelled on the plane since taking office on 20 January. The Independent has contacted the White House for comment about precautions for the journey.

Although Air Force One has historically been used to describe any aircraft transporting the president, “it it is now standard practice to use the term to refer to specific planes that are equipped to transport the Commander-in-Chief,” the White House website reads.

“Today, this name refers to one of two highly customised Boeing 747-200B series aircraft, which carry the tail codes 28000 and 29000,” it adds.

The two planes, which are housed at the base in Maryland, are only referred to as Air Force One when the president is on board.

In addition to housing Air Force One, Joint Base Andrews provides services for senior US officials and is often the first stop for royals and leaders from around the world when they visit the country.

The Independent has contacted the OSI for additional comment.