The Pentagon program that will replace the pair of aging 'Air Force One' planes is already slated to cost $4.265 billion through the year 2021, according to federal budget and procurement documents obtained by DailyMail.com.

That number supports what President-elect Donald Trump said two days ago when he claimed the U.S. Air Force should cancel its order with Boeing because the project's cost had spiraled above $4 billion.

'Boeing is building a brand new 747 Air Force One for future presidents, but costs are out of control, more than $4 billion. Cancel order!' Trump tweeted Tuesday.

Critics immediately pounced, including Boeing itself – which claimed it is 'currently under contract for $170 million to help determine the capabilities of these complex military aircraft that serves the unique requirements of the president of the United States.'

That spin ignored that vast majority of the taxpayer dollars that it will collect in the future, most of which is already written into the pages of government paperwork.

Donald Trump told reporters on Tuesday that the Air Force One replacement program's costs are 'totally out of control. ... We want Boeing to make a lot of money, but not that much money'

THE FIRST $2.872 BILLION: Existing budget allocations for the new Air Force One program

AN EXTRA $330 MILLION: Just for 'facilities' costs related to the project

THE FINAL BILLION-PLUS: Money requested last year that will ultimately pay for building the twin airplanes

The Defense Department budget documents show a total of $2.872 billion in existing and planned spending on the main Boeing project between 2015 and 2021, all for Research, Development, Test & Evaluation – or RDT&E, in government-speak.

A separate schedule identifies another $330.7 million in 'other' costs, described as 'facilities' for the Presidential Aircraft Recapitalization program – the official bureaucratic name for the catch-all Air Force One project.

All that money, however, won't get either of the two redundant planes built. That will require a separate $1.062 billion 'procurement' request, which the Pentagon spelled out last year.

Added together, the total exceeds the number that got Trump into hot water on Tuesday.

White House press secretary Josh Earnest disputed Trump's claim during a briefing with reporters Tuesday aboard the current Air Force One.

Air Force One, the president's 'mobile Oval Office,' boasts 4,000 square feet of space, classified communications gear, missile defenses and a surgical suite

The new Air Force One is being built on the platform of Boeing's newest flagship, the 747-8 series jumbo jet

Trump set off a firestorm Tuesday morning by tweeting that the U.S. Air Force should 'cancel' its order for new Air Force One jets because of cost overruns at Boeing

'Some of the statistics that have been cited, shall we say, don't appear to reflect the nature of the financial agreement between Boeing and the Department of Defense,' Earnest insisted.

That has turned out to be inaccurate.

Trump's communications aides did not respond Thursday to requests for comment. They also did not have documents at the ready on Tuesday to justify the president-elect's claim about the overall cost of replacing the presidential aircraft.

Spokesman Jason Miller told reporters during a conference call on Tuesday that 'when you look at the cost of the two new Air Force Ones plus the research and development, the overall program cost, it's a pretty big number.'

Defense contractors' costs for RDT&E often amount to more than the final price of creating a vehicle or a weapon.

Instead of citing specifics, however, Miller defended Trump by pointing more generally to his 'focus on keeping costs down across the board with regard to government spending.'

The current plane includes a spacious nose-cone suite for the president, a small section in the rear for reporters, and two galleys

Parts of the current Air Force One plane look more like an office than an aircraft

It turns out that Trump was right about the Air Force One project's overall cost projection but it's unclear how he learned the information

Trump suggested in a rare visit to the lobby of Trump Tower on Tuesday that the Boeing contract could be continued once he moves to Washington because he wants Boeing to be profitable – to a point.

'The plane is totally out of control. It's going to be over $4 billion – it's for [the] Air Force One program. And I think it's ridiculous,' Trump said. 'I think Boeing is doing a little bit of a number. We want Boeing to make a lot of money, but not that much money.'

Trump complained about the current presidential planes as he campaigned for president, typically when he criticized President Barack Obama for flying to Hawaii in Air Force One – with its 'aging engines' that 'spew stuff' into the environment – following remarks about carbon emissions and global warming.

The current Air Force One planes will reach the end of their expected useful lives in 2017.

OUT WITH THE OLD 747-200B ... AND IN WITH THE NEW 747-8 THE OLD AIR FORCE ONE Frame: 747-200B Space: 4,000 square feet Range: 6,865 nautical miles Communication: Phone, WiFi Costs: $180,000 an hour Weight capacity: 144,690 lbs Fuel capacity: 52,410 gallons Max seating: 452 passengers Length: 231.6 feet Wingspan: 195.50 feet Rooms: Office, conference room, bedroom, medical suite / operating room THE NEW AIR FORCE ONE Frame: 747-8 Space: 4,786 square feet Range: 8,000 nautical miles Communication: Phone, WiFi Costs: Unknown Weight capacity: 165,345lbs Fuel capacity: 64,055 gallons Max seating: 700 passengers Length: 250.30 feet Wingspan: 224.70 feet Rooms: Unknown Advertisement

Air Force One isn't a garden-variety 747: It's outfitted with proprietary military technology including classified communications gear and defenses against missile attacks.

The 'mobile Oval Office' includes 4,000 square feet of space on three separate levels. The president and his guests have the use of a conference room, a dining room, senior staff offices and even a medical operating room – for the doctor who comes along with every flight.

The plane's on-board electronics are also hardened to protect against the electromagnetic pulses created during a nuclear explosion.

Trump, a real estate CEO, has set an unusual tone early in his transition process, personally intervening to tweak how individual companies are doing business.

Last week he announced a change of tack for Carrier, an Indiana company that pledged to keep 1,100 jobs in the U.S. – instead of moving them to Mexico – after Trump brokered a deal with the state government, run by governor and vice president-elect Mike Pence.

Trump himself reported owning stock in Boeing worth between $50,001 and $100,000 when he filed a lengthy financial disclosure earlier this year.