President Donald Trump says he is considering buying used Boeing aircraft — perhaps from an overseas seller — to use as Air Force One when he’s aboard, as he fumes over the U.S. plane-maker’s delays in producing two specially modified ones for presidential use.

Boeing has had six years of production problems, safety issues, delivery delays and unhappy buyers of its aircraft. But President Donald Trump’s anger at the delays for the next generation of Air Force One jets could result in a huge blow to what remains of the company’s prestige and finances going forward.

Boeing CEO Kelly Ortberg on Thursday said Elon Musk, the head of its space business rival SpaceX, is "helping us a lot" in navigating through delays in delivering Boeing's Air Force One presidential jet.