Politics Donald Trump just took a shot at Boeing in Trump Tower

President-elect Donald Trump unexpectedly started negotiating with Boeing (BA) over the price of a new Air Force One on Tuesday morning.

First over Twitter (TWTR), Trump threatened to cancel the order for a new Air Force One, which would be used for future presidents. He said the cost of the new 747 was more than $4 billion.

Then in the Trump Tower lobby, the president-elect amplified his message.

"Well the plane is totally out of control, it's going to be over $4 billion for Air Force One program," he said. "I think it's ridiculous, 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."

In January, Boeing won a contract to start preliminary work on a new Air Force One program. The Air Force awarded Boeing an initial contract worth nearly $26 million to reduce risk and lower cost, Reuters reported. The Air Force has previously said that it planned $1.65 billion for two replacement jets, Reuters reported.

Noting that the current Air Force One is 25 years old, a source familiar with the Boeing Air Force One contract told CNBC that if the program does not move forward, it could be years before the president ever flies on a new one.

In a statement, Boeing said: "We are 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. We look forward to working with the US Air Force on subsequent phases of the program allowing us to deliver the best planes for the President at the best value for the American taxpayer."

According to the Department of Defense budget there's about $2.8 billion dollars allotted on the project until fiscal 2021. The document didn't put a total figure on the cost. The figure was marked as "continuing" under cost to complete.

Before Trump's tweet, Boeing was trading at $152.16 a share. After the tweet, it fell, 1.6 percent to a low of $149.75 a share, according to FactSet. Within the first hour of trading, shares of Boeing were down about 0.5 percent.

In Trump's 2016 financial disclosure, filed in May, he listed owning $50,001 to $100,000 of Boeing shares and listed the income from those dividends at $1,001 to $2,500. Trump's spokesperson Jason Miller reportedly said the president-elect sold all of his Boeing stock back in June.

Last month, a report said that Trump can get paid for Secret Service agents that fly on his plane.

The stock is up more than 5 percent year to date.

—CNBC's Steven Kopack and Eamon Javers contributed to this report.

• Top News and Analysis
• Latest News Video
• Personal Finance