Mexico’s Andres Manuel Lopez Obrador promised to seek friendly ties with the United States, shortly after claiming a landslide victory in the country’s presidential election.

On the back of widespread frustration over endemic corruption and brutal violence, the 64-year-old former Mexico City mayor won around 53 percent of the vote, according to an official projection of results.

It marks the first time in Mexico’s modern history that a candidate has won more than half of the vote in a competitive election and an unambiguous rejection of the two traditional mainstream parties that have governed the country for nearly a century.

During the campaign Lopez Obrador regularly used confrontational language when referring to President Donald Trump. He has previously described the U.S. president as “erratic and arrogant.”

Nonetheless, he soon sought to adopt a much more conciliatory tone in a victory speech late Sunday, saying he would seek “friendly relations” with the U.S.

Political ties between Mexico City and Washington have been strained since the election of Trump, who has routinely criticized the Latin American country over trade and migration. However, the U.S. president appeared ready to try to start things off on the right foot.

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“I look very much forward to working with him,” he tweeted Sunday shortly after several of Lopez Obrador’s political rivals had conceded defeat, before adding: “There is much to be done that will benefit both the United States and Mexico!”

Duncan Wood, director of the Wilson Center’s Mexico Institute, told CNBC Monday that while Trump’s timely congratulatory message to Obrador was a “very encouraging” sign; any continuation of the U.S. president’s targeted political attacks would most definitely prompt a swift and firm response.

“Andres Manuel (Lopez Obrador) will not just sit back and take it, he will respond and that could lead to a serious deterioration of the relationship,” Wood said.

A champion of the poor, the sharp-tongued leftist lawmaker has been described by critics as a Mexican Hugo Chavez or even a Mexican Donald Trump, thanks to his nationalist and populist agenda — although he’s toned down some of his more inflammatory campaign promises like ending energy privatizations.

Mexico’s peso soared more than 1 percent shortly after initial exit polls projected Lopez Obrador would clinch victory on Sunday. But those gains were short-lived, as the currency then fell by around 0.8 percent amid reports the win could be big enough to herald a congressional majority.

The peso has since settled to trade marginally lower, as market participants reacted to Lopez Obrador’s pledge to maintain fiscal discipline and preserve central bank independence.

He’s also called the ruling political class “filthy pigs,” “hogs” and “swine” during campaign rallies, and promised a non-violent revolution. Still, his aides say that on most of his more radical pledges, he won’t actually follow through.

“He will have a very strong honeymoon period, he is going to emerge as a superstar of Latin American politics and he has the opportunity right now to do very, very important things for the country,” the Wilson Center’s Wood added.

Trump has aggravated political ties with Mexico by saying he would look to re-negotiate the North American Free Trade Agreement (NAFTA) and build a wall along the U.S.-Mexico border.

Meanwhile, Lopez Obrador has previously been critical of NAFTA, and his popularity among farmers and the working class in Mexico was seen to have increased thanks in large part to his confrontational attitude toward Trump.

“He will certainly stand up to Trump should Trump engage in destructive policies like building the wall and making Mexicans pay for the wall … That won’t happen,” Beat Wittmann, a partner at financial consultancy Porta Advisors, told CNBC’s “Squawk Box Europe” on Monday.

When asked whether global leaders could soon try to come together in order to avoid a full-blown trade war, Wittmann replied: “I don’t think that Trump will blink at this stage. I clearly think that all countries affected by tariffs will retaliate because if they don’t retaliate they will be voted out of office.”

“There is some significant anti-American sentiment building,” he added.

— CNBC’s Natasha Turak contributed to this report.