Mexico City - Mexicans are replacing profile pictures on social media with their country's flag. Others are calling for boycotts of American products like Coca-Cola and Starbucks.

US President Donald Trump's vow to make Mexicans pay for a massive border wall has not only caused a diplomatic row, it has sparked patriotic fervor south of the border.

On Twitter, Facebook and Instagram, people are using the hashtag #WeAreAllMexico, punctuating anti-Trump tweets with cries of "Viva Mexico!" and boasting that they live in "the best country in the world."

President Enrique Peña Nieto's spokesman, his foreign and finance ministers, and government departments have made the country's green, white and red flag their profile photo on Twitter.

A slew of hashtags encourage Mexicans to stay away from American goods: #AdiosProductosGringos (goodbye gringo products), #AdiosStarbucks, #AdiosMcDonalds and #AdiosCocaCola.

Telecommunications magnate Carlos Slim, the world's fourth richest man, called a rare news conference to express his "great pleasure" at the burst of national pride and support for the president, even though Peña Nieto's economic reforms have chipped away at the billionaire's telephone empire.

"This is the most surprising display of national unity that I have seen in my life," Slim said, urging Mexicans to support Peña Nieto's negotiations with the US administration.

'Proud to be Mexican'

Peña Nieto, whose popularity fell to 12 percent earlier in January after protests erupted over an increase in gasoline prices, has seized on the renewed patriotic pride.

In a video message late Monday, he touted this "national unity" and said it "must be the cornerstone of our strategy and our actions inside and outside the country."

He boasted: "Today, like never before, I feel proud to be Mexican."

Peña Nieto vowed to be firm in his defense of Mexico's "dignity and independence" from the US government, though he said that his phone conversation with Trump on Friday "opened spaces" for the two governments to continue their dialogue.

Jesus Velasco, an expert on US-Mexico relations at Tarleton State University in Texas, said that fixing ties "will take a while" because "the damage has been done."

Mexicans praised Peña Nieto for canceling a meeting with Trump in Washington scheduled for this week, after the US president ordered the construction of the wall and insisted that Mexico pay for it.

Opposition leaders rallied behind Peña Nieto and even his longtime rival, two-time leftist presidential election runner-up Andres Manuel Lopez Obrador, applauded the move.

But Peña Nieto's popularity appears to have had a limited bounce.

An opinion poll published in the daily Excelsior on Tuesday showed his approval rating rising by a handful of points to 16 percent - though the survey was conducted only among 400 Mexicans and had a five-point margin of error.

Wrapped in the flag

"Mexico tends to be a nationalist country when it is attacked from outside," said Damaso Morales, a foreign relations expert at the National Autonomous University of Mexico.

"Throughout our history, we have wrapped ourselves in the flag and thrown ourselves into a nationalism that could even be irrational," Morales said.

Morales was referring to the story - some say legend - of a cadet who draped himself with the Mexican flag and jumped to his death from the Chapultepec Castle in Mexico City rather than live to see US forces grab it during a war in 1847.

But Javier Oliva, a Mexican political and security expert at the London School of Economics, said Mexico's nationalism is merely "reactive" and does not pose a threat.

"One of the things that we have to thank Trump for is that the world now knows where Mexico is," Oliva said.