Mr. Trump hinted that Mr. Musk's government efficiency team had found irregularities when it examined US Treasury data, suggesting that it could result in the US withholding some of its payments. "There could be a problem, and we've been looking at that, with the US national debt," Mr. Trump said on Sunday on his way to the Super Bowl aboard Air Force One. "It could be an interesting problem because a lot of things don't count," he said. "That way we might have less debt than we think." (Kim Ten)