Sen. Richard Blumenthal is calling for a response from the U.S. State Department after reports surfaced about $400 million worth of contracts for armored vehicles produced by Tesla.

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.