In the closing days of his campaign, Donald Trump vilified one of the world’s richest men – Mexican billionaire Carlos Slim – as part of a globalist cabal conspiring to extinguish his populist candidacy.

Yet over the weekend, Slim journeyed to Mar-a-Lago, Trump’s estate in Palm Beach, Florida, for what the president-elect described as “a lovely dinner with a wonderful man.”

The peacemaking gesture – the culmination of weeks of back-channel negotiations that included a secret visit to Mexico City by a Trump envoy – signals a possible thawing between Trump and Mexico’s business and political elite, whom he had used relentlessly as a foil throughout his campaign.

The communications raised hopes in Mexico’s business community that Trump might reconsider his vow to tear up the North American Free Trade Agreement and be persuaded to adopt less hard-line immigration and economic policies, which were cornerstones of his campaign.

Larry Rubin, president of the American Society of Mexico and a key liaison between Republican officials in the United States and Mexican leaders, said Trump and his team are forging a better understanding of shared economic interests between the two countries.

“What President-elect Trump wants to do in coming closer to the Mexican business community has an impact not only nationally but regionally with Latin America and opens the doors for good business relations overall,” said Rubin, who is one of several candidates to serve as Trump’s ambassador to Mexico. “The closer that the administration is to businesses and governments in Mexico and in the region, the better for the U.S.”

But Trump has made no declaration of any shift in his immigration or trade policies, and any softening would carry the risk of angering his core supporters.

Saturday, just hours before his dinner with Slim, Trump staged the final rally of his “thank you” tour in Mobile, Alabama, and the crowd chanted, “Build that wall!”

“Do not worry. We are going to build the wall,” Trump said, reiterating his promise to erect a wall along the U.S.-Mexico border to keep out undocumented immigrants and to make Mexico pay for it.

Trump and Slim’s dinner was designed to open a friendly line of communication rather than delve into policy details, according to people briefed on the discussions.

Slim’s visit to Mar-a-Lago came after Corey Lewandowski, a former Trump campaign manager who remains a confidant of the president-elect, quietly visited Mexico City on Dec. 9 to meet with Slim.

After the election, Slim connected with Lewandowski – someone he saw as having Trump’s ear but not as a formal member of his staff – and arranged for them to discuss trade, economic and other issues, according to people with knowledge of the session.

Slim has long been the dominant figure in Mexico’s business community. He has a net worth estimated at $77 billion, according to the most recent tally by Forbes magazine. He controls Latin America’s largest telecom company, América Móvil, and is involved in banking, construction, retail, health-care, oil and other businesses. Slim also is the largest single investor in the New York Times Co.

Reuters/Carlos Jasso

Carlos Slim’s wealth – estimated at $77 billion – amounts to a noticeable chunk of Mexico’s gross domestic product.Reuters/Carlos Jasso

Trump’s meeting with Slim is the latest example of the president-elect reconciling with former foes – most prominently, Mitt Romney, the 2012 GOP presidential nominee who had led the Republican resistance to Trump’s candidacy but became a serious candidate for secretary of state.

During the campaign, Slim strongly criticized Trump’s rhetoric about Mexican Americans as well as his plans to renegotiate NAFTA and build the border wall. Slim said Trump’s proposed tariff on imports would “destroy” the U.S. economy.

Trump in turn accused Slim of helping promote his Democratic opponent, Hillary Clinton, and cast him as part of a global conspiracy. At an Oct. 14 rally, Trump attacked Slim personally and accused Times journalists of being “corporate lobbyists for Carlos Slim.”

Trump’s quarrel with Slim extends to the very beginning of his campaign. At his June 2015 announcement speech, Trump’s remarks about undocumented Mexican immigrants being criminals and rapists sparked an intense furor. A television company controlled by Slim canceled a project it had been working on with Trump’s company, and Slim’s spokesman said Trump was “close-minded” and his comments “totally out of line.”

Trump told friends at the time that he believed Slim – who once had a business relationship with a rival candidate, former Florida Gov. Jeb Bush – helped orchestrate the public backlash.

“He believes Carlos Slim was behind a lot of his problems,” said one Trump friend, who spoke on the condition of anonymity to be candid. This person suggested that Trump sees a benefit to Saturday’s dinner: “He wants to neutralize him.”

After Trump’s unexpected victory, Slim’s tone toward the president-elect changed. In recent comments, Slim has spoken optimistically about Trump’s presidency. “If Trump is able to grow the United States economy and jobs, that would be fantastic for Mexico,” Slim told a business forum.

Slim’s evolution comes as the Mexican government is undertaking an extensive effort to preserve NAFTA by proving Mexico’s worth to the U.S. economy. Since Trump’s win, Mexican diplomats have sought to spread the message to immigrants, through the network of 50 consulates in the United States, about their rights and legal protections.

The Mexican government has enlisted business executives in both countries to talk about the economic benefits of free trade in what one Mexican official described as “the language that the new president speaks: deals and entrepreneurial vision.”

Mexican officials have readied themselves to discuss NAFTA, or any other topic, with the incoming administration. But they have also stressed that they don’t yet know what policies Trump intends to pursue.

“The truth is right now we don’t even have a [negotiating] table,” Paulo Carreño, Mexico’s deputy foreign secretary for North American affairs, said in a recent interview.

While Trump’s election has presented challenges for Mexico, Carreño said, the government remains “cautiously optimistic” about the prospects for the bilateral relationship.

Carlos Sada, Mexico’s ambassador to the United States, said in a speech last week to the Council of the Americas that his country would “work to find common ground with the next U.S. administration.”

Sada added, “Besides my basic efforts to get to know better the character of the U.S. president-elect, we have to seriously recognize the juncture at which we are standing today: We either capitalize it and turn it into opportunity for the sake of a new stage of our integration and shared growth or risk a major setback.”

A group of chief executives from both countries met in Mexico City recently for a public policy summit chaired by Tom Donohue, president of the U.S. Chamber of Commerce; John Rice, vice chairman of General Electric; Juan Pablo Castañón, chairman of the Consejo Coordinador Empresarial, a Mexican private-sector business council; and Armando Garza, chairman of Alfa, a Mexican-based multinational conglomerate.

Mexican President Enrique Peña Nieto and a number of his ministers attended the session, where business leaders discussed the impact of Trump’s election on cross-border trade and other economic matters, according to people familiar with the meeting.

Earl Anthony Wayne, a former U.S. ambassador to Mexico under President Barack Obama, said there is “a lot of concern and a desire to find a positive way forward.”

“It’s a million dollars a minute in trade that goes across our border,” Wayne said. “The CEOs are very interested in preserving what they see as mutually beneficial relations. There’s a lot of attention to what the policies will turn out to be and a desire to have a dialogue with whoever the new officials will be.”

In August, Trump made a splashy visit to Mexico City to meet with Peña Nieto, where the then-candidate was unusually subdued and struck a cooperative tone with the Mexican leader. Trump said at a joint news conference that day that he and Peña Nieto did not discuss who would pay for his proposed border wall, despite his campaign-trail vow to compel Mexico to foot the bill.

Slim’s mark can be seen all across Mexico City, from the glittering Museo Soumaya, an hourglass-shaped building made of aluminum tiles and named after his late wife, to the Sanborns department stores that dot so many corners. His wealth amounts to a noticeable chunk of the country’s gross domestic product.

In a 2013 appearance on CBS’ “Late Show With David Letterman,” Trump told the host that Slim was a “good guy” with “a lot of money.”

When Letterman detailed the towering nature of Slim’s fortune, however, Trump smiled. “I don’t feel so good when you mention Carlos Slim,” he said, “but that’s OK.”

Partlow reported from Tijuana, Mexico. Karen DeYoung contributed to this report from Washington.