An intruder made it aboard an aircraft belonging to the unit responsible for Air Force One after entering Joint Base Andrews without authorization Thursday, leading to a security review of bases around the world, according to military officials.
"The individual gained unauthorized access to the flightline and entered a C-40 aircraft assigned to the 89th Airlift Wing," said a statement from base public affairs Friday. "Joint Base Andrews Security Forces responded, detained and interviewed the individual."
The 89th Airlift Wing is responsible for flying the president aboard the VC-25 aircraft commonly referred to as Air Force One, as well as the vice president, Cabinet members and other senior officials with its fleet of planes.
No aircraft used by the president were at risk from the trespasser, a U.S. official told ABC News. The official said an Air Force historian checked the records and found no instance of a U.S. president flying aboard a C-40.
The official added that the C-40 was on the flight line when the intruder entered. This suggests the plane was not in the immediate area of Air Force One, which would have been inside a hangar.
"The man was unarmed and did not harm any personnel and there is no indication that the individual has any links to extremist groups," according to the statement.
After assisting with the interview, the Air Force Office of Special Investigations booked the man and gave him a federal summons for trespassing, the statement said. He was then turned over to local police due to having two outstanding warrants, it added.
The OSI did not immediately respond to ABC News' request for comment and additional details.
The secretary and chief of staff of the Air Force directed the service's Inspector General to investigate the security breach, according to a statement released by the Air Force Friday afternoon.
"This review and investigation will also include their installations worldwide," Pentagon press secretary John Kirby said in a press briefing Friday. "They're going to investigate this incident, but they're also going to take a look at security protocols across the force."
Kirby told reporters that the base had already adjusted some of its security protocols by Friday morning but would not give details.
"The security of our installation is paramount," said Col. Roy Oberhaus, vice wing commander of the 316th Wing at Joint Base Andrews. "This was a serious breach of security and Joint Base Andrews is investigating the incident to determine how this happened so it doesn't happen again."
According to the Air Force, the C-40 aircraft is a nearly identical military version of the Boeing 737-700 business jet and is primarily used to transport combatant commanders as well as members of the Cabinet and Congress.
Joint Base Andrews is located in Prince George's County, Maryland, about a 14-mile drive southeast of Washington, D.C.
President Joe Biden is scheduled to make his first flight aboard Air Force One from the base en route to Wilmington, Delaware, Friday evening.
ABC News' Luis Martinez contributed to this report.