Bloomberg reports that Air Force spokesperson Col. Pat Ryder had no response for repeated inquiries about a claim Trump made during a rally last week that “we got that price down by over $1 billion.”

Trump was referring to a program including the development and purchase of two Boeing jets (BA) to be used as Air Force One, a deal that the President claimed was originally expected to cost about $4.2 billion.

“Can you believe this?” Trump said to a crowd of his supporters in Florida. “I said, ‘No way.’ I said, ‘I refuse to fly in a $4.2 billion airplane. I refuse.’” Before taking office, he had threatened to revoke the deal amid an ongoing public spat with the aircraft maker.

For more on Trump and Boeing, watch Fortune’s video:

Asked about the claim on Wednesday, Ryder told reporters that to his knowledge, “I have not been told that we have that information,” adding that, “I refer you to the White House” for all further inquiries.

A preliminary phase of planning upgrades for the President’s aging Air force One is already under way with a $170 million contract, according to a statement by Boeing. Around mid-year the Air Force plans to award contracts for two Boeing 747-8 aircraft, considered the only U.S.-manufactured planes appropriate for the role.

Air Force One serves as a mobile office for the President, and as such is outfitted with advanced security systems and able to refuel in mid-air. The Air Force said it has budgeted $2.7 billion this year for maintenance and upgrades to the President’s flying fortress.