The State Department had been in talks with Elon Musk's Tesla company to buy armored electric vehicles, but the plans have been put on hold by the Trump administration after reports emerged about a potential $400-million purchase.

The case is a reminder of how much of Musk’s wealth comes from taxpayers. His companies have government contracts worth hundreds of millions of dollars a year.

The State Department said it planned to embark on a giant purchase of armored vehicles from Tesla, before the listing was edited to omit any reference to Elon Musk’s company.