Former president Vicente Fox: Mexico 'not going to pay for that (expletive) wall'

The Trump-Fox Twitter feud continues.

Former Mexican President Vicente Fox Quesada on Wednesday resumed his profane assault on President Trump's plan to build a wall along the Mexican border and make the country pay for it.

White House press secretary "Sean Spicer, I've said this to @realDonaldTrump and now I'll tell you: Mexico is not going to pay for that (expletive) wall," Fox tweeted. He even has a hashtag for his obscene language.

Trump spoke Wednesday about his executive order to "begin immediate construction of a border wall" that Mexico eventually would finance, a pledge that was a centerpiece of his campaign for president.

Fox has trolled Trump on Twitter repeatedly, vowing that Mexico will never pay for the wall and asking if Trump is a "legitimate president."

The executive order Trump signed Wednesday instructed executive branch agencies to identify all federal assistance they sent to Mexico over the past five years. That includes all "bilateral and multinational development aid, economic assistance, humanitarian aid and military aid."

Trump says border wall will 'also help Mexico'

The agencies are required to submit a report within 30 days outlining those funds, which could be used as leverage to get Mexico to help pay for the border wall, which could cost billions to construct in areas where there is no barrier.

Fox feels strongly about the issue because as a former governor of Guanajuato, he oversaw an influx of auto manufacturing plants under the NAFTA trade deal, which Trump complains has cost the United States jobs.

Fox attempted to deepen U.S.-Mexico relations after taking office and appeared to be gaining ground on an immigration reform package, only to have the Sept. 11, 2001, terror attacks scuttle those efforts.

“His allies now turn out to be Trump’s enemies, so Fox is being true to form,” said Federico Estévez, political science professor at the Autonomous Technological Institute of Mexico. “He’s playing with [the attacks] at a circus level of rhetoric and splashiness, but he really is being true to how his vision started.”

Contributing: David Agren in Mexico City