"I lament and reject the decision of the United States to continue building a wall that for years does not unite us, but divides us," Enrique Peña Nieto said.

Ronaldo Schemidt / AFP / Getty Images

MEXICO CITY — Mexican President Enrique Peña Nieto on Thursday said he would not attend a meeting with US President Donald Trump after the latter signed an executive order to extend a wall along the USA's southern border and said Mexico would pay for it.

"We informed the White House this morning that I will not attend the work meeting scheduled for next Tuesday," he said via Twitter. The move came after a tense day during which Peña Nieto came under intense pressure from the Mexican public to cancel the meeting. "Mexico does not believe in walls," he said in an address to the Mexican public Wednesday night. "I've said it once and I'll say it again, Mexico will not pay for any wall." Trump ordered the construction of a border wall Wednesday, inching closer toward a campaign promise that threatens to fracture an already tense relationship with Mexico.

“We've been talking about this right from the beginning,” Trump said as he signed an executive order launching the process of "immediately" building a physical wall between the United States and Mexico. The action, taken less than a week before Peña Nieto was scheduled to visit his US counterpart, quickly drew calls for the meeting between the two to be canceled.

Pablo Martinez Monsivais / AP

A person familiar with the matter said Peña Nieto was "considering" canceling the visit as of Wednesday afternoon, but spoke on condition of anonymity because plans had not been finalized.

In an interview Wednesday night with ABC News, Trump insisted Mexico would pay for the wall, saying, "there will be a payment. It will be in a form,

perhaps a complicated form." And on Thursday morning, he tweeted about the planned Peña Nieto meeting, saying, "If Mexico is unwilling to pay for the badly needed wall, then it would be better to cancel the upcoming meeting." In a message to Mexico, Peña Nieto criticized Trump's decision to continue construction of a wall but did not address whether or not he would follow through on his visit Tuesday. He criticized the executive order, which he said only brought distance between the two nations. In response, he said he was asking his secretary of state to enact protections for immigrants abroad. In effect, Peña Nieto said, the 50 consulates in the US will be become immigrant rights centers to protect their rights. "Where there is a Mexican at risk that needs our backing, we should be there," he said. "His country should be there." Construction of the concrete wall dividing the two countries, which Trump has said will be as high as 55 feet, was indeed one of Trump's first promises on the campaign trail. Further rousing the ire of his southern neighbors, Trump, in the same speech where he announced he was running for president, accused Mexico of sending criminals and "rapists" across the border and promised to deport millions of undocumented immigrants, the majority of them Mexican. But of all his pledges, the wall has become the most controversial in Mexico. After a visit to Mexico two months before the election, Trump and Peña Nieto engaged in a Twitter tit-for-tat over who would pay for the colossal project — Trump repeatedly insisted that Mexico would bear the financial burden — which is seen by many as an affront to Mexico’s dignity. The executive branch will "develop long-term funding requirements for the wall, including preparing Congressional budget requests for the current and upcoming fiscal years," according to the executive order signed by Trump. Trump and Peña Nieto were scheduled to meet next Tuesday. But some people said that Wednesday’s announcement should make the Mexican leader reconsider his tone and perhaps even the encounter. “There shouldn’t even be an intention [on the part of Peña Nieto] to sit down and have a formal talk,” Armando Ríos Piter, a senator who has campaigned against Mexico paying for the wall, told BuzzFeed News, echoing dozens of Mexicans on Twitter.

Christian Torres / AP

The construction of the wall is “an act of enmity, a hostile act,” Ríos Piter said. “Let’s not get lost in minutiae,” he added, speaking about who would finance the wall. Ríos Piter has proposed instituting roadblocks in legislation so that no public funds go toward building the wall. Andrés Manuel López Obrador, the frontrunner for next year's presidential election in Mexico — a left-wing populist — said Mexico will take the case of Trump's border wall to an international tribunal.

Presidente Trump: su muro nos agrede y deja la Estatua de la Libertad como leyenda. Iremos a tribunales internacionales. Viva la fraternidad