Wall? What wall?

Citigroup,  (C - Get Report)  which owns Mexico's second-largest bank, appears undaunted by Republican presidential nominee Donald Trump's proposal to build an impenetrable barrier along the border.

The U.S. lender said Tuesday it will put an additional $1 billion into operations in Mexico over the next four years, on top of a $1.5 billion capital injection announced in 2014. The money will be used to add 2,500 new ATMs and revamp some branches in Mexico City, Guadalajara and Monterey to offer high-level, personalized advice along with "smart-banking technology." Citigroup also will spend money to rebrand the Mexican unit as "Citibanamex" from the current "Banamex."

The capital injection by Citigroup follows the Mexican peso's 15% slide against the dollar in the past year, a decline driven at least partly by investor concerns that if Trump is elected, he would push for tougher border controls and roll back trade agreements between the U.S. and its southern neighbor. Several U.S. CEOs, including General Electric's  (GE - Get Report) Jeff Immelt and Hewlett Packard's  (HP - Get Report) Meg Whitman, have publicly denounced Trump's critical stance on immigration and Mexican citizens.

"If Trump gets elected, there's no question there's going to be a problem with Mexican trade," said Dick Bove, a bank analyst at Rafferty Capital Markets. "The peso would go down, there would be a problem in the Mexican economy, it would affect Citigroup's position in Mexico, and it would be very unpleasant."

Citigroup CEO Michael Corbat said in a statement that the investments "reaffirm our commitment to Mexico and our confidence in its prospects."

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As of June, Citigroup's Mexican holding company, Grupo Financiero Banamex, had 181.5 billion pesos ($9.4 billion) of capital, according to a quarterly report.

Based on that figure, Citigroup's investment represents an 11% capital increase at the current exchange rate -- further than the capital would have gone when the peso was stronger.

Citigroup bought Banamex for $12.5 billion in 2001 as an anchor for its operations in Latin America, which was supposed to provide faster revenue growth than in the U.S. In recent years, however, the Mexican operations have generated headaches, including suits over money-laundering and an alleged loan fraud involving the offshore oil-services company Oceanografia.

Profit at Citigroup's Latin America consumer business fell last year, primarily due to higher regulatory and compliance costs, higher technology spending and mandatory salary increases in certain countries, according to the New York-based company's annual report. The results included losses related to the collapse of Mexico's homebuilding industry in 2013.

"The thing went totally off the tracks because they didn't have a clue what was going on down there," Bove said.

Jennifer Lowney, a Citigroup spokeswoman, declined to comment on whether the latest investment was the result of pressure from regulators in the U.S. or Mexico to improve the bank's operations or controls south of the border.

Still, the investment, and Corbat's rebranding of the unit, signal that he has little intention of divesting the Mexican operations, a move some analysts have recommended as a way of further shrinking the bank following its $45 billion bailout in 2008.

As recently as July, the CLSA analyst Mike Mayo asked Corbat what, if anything, would prompt him to sell the Mexican operations.

"We like the demographics of Mexico, the growth prospects," Corbat responded, according to a company transcript. "Right now, growth in the world's a pretty tough thing to find. We think Mexico offers that."

Lowney declined to say whether the peso's recent decline contributed to the decision to invest more in the country, but Citigroup's own analysts have said that uncertainty over the U.S. election has led to a "perverse dynamic, creating an additional bias against the Mexican currency."

And that slide has opened up room for appreciation in the peso: According to a Sept. 30 report, Citigroup analysts project it will strengthen to 18.50 per U.S. dollar, from the current rate of about 19.3 per dollar.