"They can pay for it indirectly through NAFTA," he told the newspaper in an interview. "We make a good deal on NAFTA, and, say, I'm going to take a small percentage of that money and it's going toward the wall. Guess what? Mexico's paying."

Mexico will pay for the wall — "indirectly," President Donald Trump claimed Thursday. Trump told The Wall Street Journal that the United States' southern neighbor could end up funding the proposed structure on its border with the U.S. if the North American Free Trade Agreement gets tweaked.

It is unclear what mechanism would go into NAFTA that would cause Mexico to indirectly pay for the structure, which Trump promised as a candidate. Last year, the administration floated a possible 20 percent border tax on goods coming from Mexico, before walking back the idea.

Trump has repeatedly said he could withdraw from the pact among the U.S., Mexico and Canada if he cannot secure terms that he deems more fair to the U.S. The president told the Journal that he wants a fair deal, or a "Trump deal," as talks about revisions to the pact continue among the three countries.

He added that he will leave his decision on a deal "a little bit flexible" as Mexico has a presidential election this year, which "makes it a little bit difficult for them."

Trump has called for funding for a border wall in immigration legislation that Congress hopes to agree on soon.

Read the full Journal story here.