If U.S. taxpayers front the Trump administration's border wall, the average household could owe $120.

The U.S.-Mexico border barrier that President Donald Trump pushed forward with this week could cost a projected $15 billion, according to Senate Majority Leader Mitch McConnell, R-Ky. That bill would come out to $120 per household, based on the latest Census data of U.S. households, according to the nonpartisan Committee for a Responsible Federal Budget.

Trump has repeatedly said that Mexico will pay for the project, despite insistence to the contrary by Mexican President Enrique Pena Nieto. Without an alternative funding method, the bill could fall on taxpayers.

The White House on Thursday floated a 20 percent border tax as a possible method to pay for the wall. Still, that could also pass costs along to consumers, as some goods would become more expensive.

White House spokesman Sean Spicer said the plan could bring offsetting "dynamic" benefits. He said consumers are "paying for the flood of illegal immigration coming in and the cost to U.S. workers from that" and "increased costs to secure the border and border agents."