President Donald Trump boards Air Force One as he departs Joint Base Andrews in Maryland, June 13, 2017.

Kevin Lamarque | Reuters

President Donald Trump boards Air Force One as he departs Joint Base Andrews in Maryland, June 13, 2017.

The White House has confirmed that the administration has reached a deal with Boeing for two new Air Force One planes, according to NBC News.

“President Trump has reached an informal deal with Boeing on a fixed price contract for the new Air Force One Program,” a White House spokesman said. “Thanks to the President’s negotiations, the contract will save the taxpayers more than $1.4 Billion.”

The deal between the Trump administration and Boeing is expected to total $3.9 billion. The Pentagon referred questions to the White House.

In December 2016, Trump complained of the projected cost of building a new Air Force One plane, and threatened to cancel the “order.”

The original estimate for the two new planes and their development program totaled over $5 billion. The White House credited Trump’s negotiations with the aircraft manufacturer for the smaller bill in the final deal.

Before his inauguration, then President-elect Trump met with the CEOs of Boeing and Lockheed Martin at his Mar-a-Lago resort in Florida and discussed ways to lower the cost of the planes’ development. After that meeting, Muilenberg gave Trump his “personal commitment” that Boeing would lower costs below $4 billion.

In a tweet on Tuesday, Boeing celebrated the deal that it says will provide “American Presidents with a flying White House at outstanding value to taxpayers.”

The aircraft themselves only account for about a fifth of the cost, said Richard Aboulafia, vice president of the aviation analysis firm Teal Group. Much of the cost comes from outfitting the planes for the president, including ensuring communication equipment is secure and the plane is self-sufficient.

“The planes are just a minority cost of the program,” Aboulafia said.

The Boeing 747-8 was first selected to serve as the next Air Force One in January 2015. The 747-8 and France’s Airbus A380 were the only two four-engine plane designs with a wide enough body to accommodate the needs of a presidential carrier, according to the Air Force.

This story is developing. Please check back for updates.

–CNBC’s Amanda Macias and Leslie Josephs contributed to this report.