Air Force One, the military-spec jet liner that ferries President Donald Trump around the globe, is to receive a $24m (£17m) refrigerator upgrade.

Boeing was handed the contract to design and install two gigantic chillers on the aircraft that will store enough food to keep crew members, travelling journalists, Mr Trump and his advisers going for weeks at a time.

The current units have been running for more than a quarter of a century, according to the US Air Force (USAF), and have become unreliable.

Air Force One is the name of whichever of two VC-25 planes – which are modified 747s – the President is flying in.

Work is expected to be completed in October 2019, a Department of Defence contract notice said.

“The current rear lower lobe cold chiller units being replaced are the original commercial equipment delivered with the aircraft in 1990.

“The units were based on the technology at the time and designed for short-term food storage”, a USAF spokesperson told CNN.

She added: “Although serviced on a regular basis, reliability has decreased with failures increasing, especially in hot/humid environments.

“The units and associated aircrafts’ structural modifications are being specially designed to provide nearly 70 cubic ft of temperature-controlled (refrigeration/freezer) storage to support onboard personnel for an extended period of time, without having to restock while abroad.”

How US Presidents have aged during their time in office Show all 16 1 /16 How US Presidents have aged during their time in office How US Presidents have aged during their time in office Barack Obama holds his 2015 end of year press conference at the White House Reuters How US Presidents have aged during their time in office Obama takes the oath of office on his Inauguration Day in January 2009 Reuters How US Presidents have aged during their time in office George W Bush makes a phone call shortly after the 2000 election Reuters How US Presidents have aged during their time in office Bush fields questions during his final White House press briefing on January 12, 2009 Reuters How US Presidents have aged during their time in office Hillary Clinton whispers to then-President-elect Bill Clinton at a dinner several days before his first inauguration in 1993 Reuters How US Presidents have aged during their time in office Clinton gives a brief speech toward the end of his term in October 2000 Reuters How US Presidents have aged during their time in office Appearing without his trademark glasses, then-Vice President George H W Bush answers a question at the second presidential debate in October 1988 AP How US Presidents have aged during their time in office Bush addresses a crowd of veterans during a ceremony at the Korean War Memorial in June 1992, several months before losing the presidential election AP How US Presidents have aged during their time in office Former President Ronald Reagan and first lady Nancy Reagan greet fans lined up in Washington at his first inauguration in January 1981 AP How US Presidents have aged during their time in office Reagan returns to Washington after his final trip as president to Camp David in January 1989 AP How US Presidents have aged during their time in office Jimmy Carter emerges from a Georgia voting booth on Election Day in November 1976 AP How US Presidents have aged during their time in office A photographer captures Carter preparing for his farewell address to the nation in January 1981 AP How US Presidents have aged during their time in office President Richard Nixon gives a press conference in the East Room of the White House several weeks after being sworn in in 1969 AP How US Presidents have aged during their time in office In this photo, a glassy-eyed Nixon delivers a final speech for White House staff and members of his cabinet AP How US Presidents have aged during their time in office President Lyndon Johnson proclaims a day of mourning for deceased President John F. Kennedy shortly after being sworn in AP How US Presidents have aged during their time in office Johnson, who didn't visibly age too much in his five-year tenure, joins Nixon shortly after Nixon is elected president in November 1968 AP

Eric Schultz, a former senior adviser to President Barack Obama, joked on Twitter that “we would have been impeached” for incurring similar costs.

Air Force One is not merely a transport plane but a three-deck, 4,000-sq-ft mobile command centre, hardened against electromagnetic attack and with secure communication facilities and a medical bay.

The pair of radically customised Boeing 747s can also refuel in-flight and their galleys can feed 100 people at a time.

Running one for just an hour is thought to cost some $200,000 (£141,000).

The USAF is planning to buy two replacement planes to serve as the new Air Force One – a pair of Boeing 747-8s.

The defence giant claims the new, larger version can fly further and faster than the old 747-200, while pumping out 16 tons less carbon dioxide “per trip”.

But in December 2016, before he took office, Mr Trump tweeted that the cost of the programme was “out of control” and urged its cancellation.

The order appears still to be on track, with the aircraft due to enter service in 2024.

Lyndon B Johnson is sworn in as President on Air Force One, 22 November, 1963 (Getty) (GETTY IMAGES)

Before the current 1990s-vintage VC-25s, US Presidents flew aboard Boeing VC-137Cs. The modified 707 airliners, first tail number SAM 26000 and later SAM 27000, served chief executives from John F Kennedy to George H W Bush.

Famously, following Mr Kennedy’s assassination in November 1963, Lyndon B Johnson was sworn into office aboard Air Force One – SAM 26000 – while standing beside the killed President’s widow, Jacqueline Kennedy.

The first President to fly while in office was Franklin D Roosevelt, who boarded a Boeing Model 314 Clipper seaplane to meet with Winston Churchill in Casablanca in 1943.