By Andrea Shalal

WEST PALM BEACH, Florida (Reuters) -The Air Force One program may be further delayed until 2029 or years later, a senior administration official said, citing supply chain issues and changing requirements, after the White House said the project failed to deliver a new plane on time over the weekend.

The delays are frustrating, but not much can be done to speed delivery, the official told Reuters, noting that Boeing faced problems getting components since some manufacturers had gone out of business.

Some requirements for the aircraft had also changed, given evolving potential threats, the official said.

Boeing referred questions about the schedule of the program, known as VC-25B, to the U.S. Air Force which was not immediately available for comment.

"Clearly, the president would like the airplane earlier, and so we're working to see what could be done to accomplish that," Boeing CEO Kelly Ortberg told Reuters in January.

The first aircraft was slated for delivery in December 2024, but Boeing has pushed its delivery off until at least 2027 or 2028 - towards the end of Trump's second term in office. 

Digital magazine Breaking Defense in December reported that the presidential aircraft program faced new delays that could push delivery of the first jet to 2029 or later. 

Asked about the report, the administration official acknowledged the fresh delays and the delay could stretch "years beyond" 2029.

U.S. President Donald Trump has been deeply engaged with the program since his 2016 presidential campaign, extracting a promise from then-Boeing CEO Dennis Muilenburg to cap the program's cost at $4 billion. Those fixed-price contract terms, questioned by analysts at the time and finalized in 2018, have cost Boeing over $2 billion so far.

Trump's renewed engagement could signal further problems for Boeing, whose current Ortberg said the company was meeting with Trump's billionaire cost-cutting ally Elon Musk to get the plane updated quicker, analysts said.

"The president wants those planes sooner so we're working with Elon to see what can we do to pull up the schedule of those programs," Ortberg told CNBC on Jan. 28.

Boeing leaders have said that production has been slowed by supply chain issues, high costs and the complexity of the planes that are intended to be an airborne White House.

Trump waded back into the issue on Saturday when he toured a 12-year-old 747-8 aircraft at Palm Beach International Airport, near his Florida vacation home, to get a better understanding of the configuration of the two new presidential transport aircraft, according to the White House.

The 747-8 aircraft Trump toured was formerly owned by Qatar but has since been rebuilt and now operates as a charter.

"He saw how everything was configured. It's a bigger space," the official said, adding that the current Air Force One aircraft were relatively small. The new airplane would accommodate more people, including media, the official said.