White House press secretary Sarah Sanders said Tuesday that if Congress won’t agree to an additional $5 billion toward a border wall, then President Trump would seek other government funds to pay for it.

Hours earlier, the White House indicated it could back down on its threat to shut down the government come Friday over the border wall money. But to save face, the Trump administration is twisting itself in knots trying to explain how Mexico and not U.S. taxpayers will ultimately fund the wall even as it asks for new congressional appropriations or money from other agencies.

“The president has asked every agency to look and see if they have money that can be used for that purpose, and that’s exactly what we’re doing,” Sanders told reporters during her 10-minute afternoon news briefing.

But, a reporter pressed, the deficit is over $1 trillion, so why is the American taxpayer paying for the wall when Trump as a candidate promised that Mexico would pay for it?

“We’re not asking American taxpayers for that. We are looking at existing funding through other agencies right now that we can draw on to do that in — immediately,” Sanders said. “The president has been clear that the USMCA deal would provide additional revenue through the deal that would show that Mexico has paid for the wall.” The USMCA is the administration’s proposed new trade agreement with Mexico and Canada.

Okay, let’s break this down. First, any existing funding that other agencies have in their coffers is taxpayer money. So, as many, many people pointed out on Twitter, trying to claim the money isn’t coming from the American public is either misinformed or misleading.

We asked “@TheBudgetGuy,” a.k.a. Stan Collender, in an email about Sanders’s claim. He responded: “The quick answer is that’s BS. All that is taxpayer’s money.”

The White House has been trumpeting for a long time that its new trade deal with Mexico and Canada (which has not yet been ratified by Congress) will generate enough new revenue that it will be as if Mexico is paying for the wall. (Or, in that case, is Canada paying for it?)

Sanders reasoned during the briefing that “we’re talking about additional revenue that wouldn’t have existed without the president getting a new deal” and that revenue coupled with money saved means “we can pay for the wall four times over, and by doing that new trade deal we have the opportunity to pay for the wall.”

But when a reporter followed up by asking if the White House had done the math on that, Sanders said vaguely, “There have been a number of things that we’ve looked at.”

Luckily, The Washington Post’s Philip Bump did do some math and determined that if Sanders was referring to increased tax revenue from the addition of new jobs thanks to the trade deal, the math is actually simple. If — and these are big ifs — the deal generated 10,000 new American jobs at an annual salary of $100,000 and an 18 percent federal tax rate, the wall could be paid off in as little as 100 years.

But even if the deal encouraged manufacturers not to relocate plants in Mexico or to move them back to America, that’s still not Mexico paying for the wall. It’s U.S. taxpayers.