Mexico is racing to provide tens of thousands of people with additional shelter in cities along the U.S. border, including one that declared a state of emergency ahead of Donald Trump's plan to deport a record number of migrants.

People familiar with the plans say at least 60,000 additional shelters are being prepared, focusing on people who are in the U.S. illegally and with criminal records, after the president-elect pledged to carry out the largest mass deportations in the country's history.

There are an estimated 11 million unauthorized immigrants in the United States, about half of whom are Mexican. According to Immigration and Customs Enforcement (ICE), approximately 662,000 noncitizens in the United States have been convicted of crimes or face pending criminal charges.

This week, the city of Tijuana declared a state of emergency in anticipation of the large number of people arriving, while the mayor of nearby Mexicali said the city would convert a convention center to accommodate the people.

The federal government tentatively hopes to open 25 shelters, each with a capacity of 2,500 people, to take in deported Mexicans, but the plan is being kept low-key and flexible as the numbers remain uncertain, two people familiar with the plan said .

The government declined to comment and referred the Financial Times to public information on the matter from President Claudia Sheinbaum.

Trump, who took office on Monday, threatened Mexico with a 25% tariff on all goods exported to the United States if it does not do more to prevent immigrants and drugs from crossing the border. He has legal options for deporting people, including executive orders and public health restrictions.

Scheinbaum's public response to Trump has generally been harsher than that of some other world leaders, hinting at retaliatory tariffs.

The left-wing leader said her team had plans in place to deal with the deportations but would not reveal details prematurely. The government will have to deal with the influx while imposing double-digit budget cuts to the Ministry of Foreign Affairs and the National Institute for Immigration.

A planned "panic button" app that would send an alert to the nearest consulate if migrants believe they are about to be detained for deportation has not been launched due to technical difficulties. Mexico's 53 consulates in the United States will deploy additional lawyers.

The government even released a new nationalist hymn for immigrants.

“We have been working hard for months since President Trump made this announcement to best accommodate our citizens,” Scheinbaum said this week. "Of course we don't agree with (deportation)."

Trump's tough stance on the border was one of the factors driving his victory in November's election, after border crossings to the U.S. reached record levels during Joe Biden's presidency. But Mexico reduced irregular crossings last year as it cracked down at Washington's behest and expanded legal avenues.

Deportations have been ongoing for most of U.S. history, with record numbers set in fiscal 2012 under President Barack Obama, when ICE deported more than 409,000 people. U.S. government data shows that Biden fired more than 271,000 people in fiscal year 2024.

However, both the scale and circumstances of deportations are now likely to change significantly.

During Trump's first term, Mexico brought back migrants from around the world, initially those awaiting asylum applications and later those pushed back across the border during the Covid-19 pandemic.

Sheinbaum said this month she would be open to accepting citizens of other nationalities, but it is unclear whether Mexico will take back citizens deported from the U.S. interior and near the border.

Sending migrants back to their home countries poses additional legal and practical difficulties for the United States because those countries are authoritarian regimes or lack friendly relations with Washington.

"If a Venezuelan or Nicaraguan national was arrested in Chicago after five years of living in the United States, and it was impossible to fly them to Caracas or Managua, would the administration expect Mexico to take them as well?" Washington Office on Latin America Defense Supervisory Director Adam Isaacson said.

There may not be an immediate surge as Trump faces challenges including a lack of detention space, flights and cooperation from some police forces.

Chad Wolf, Trump's former acting homeland security secretary, said the initial goal may be to exceed Obama-era deportation levels.

"My guess is if they can beat their opponents in the first year, that's a win," he told the Financial Times. "They're going to have to expand it to places they've never expanded it before. . . . It all takes time."

The economic and social impacts of the plan could be significant for both parties. U.S. industries such as construction and agriculture rely on undocumented labor, while remittances to Mexico were worth $63 billion in 2023, more than foreign investment or tourism.

People who work with immigrants in Mexico say if thousands of people are dumped into northern cities where organized crime is rampant, they will be vulnerable to gang recruitment.

Maggie Loredo, an activist working with deported immigrants in Mexico, said Mexico has historically lacked the infrastructure to reintegrate returning citizens.

“For those who are incarcerated, there’s really nothing,” she said. "These people are also in a more vulnerable situation."

Andrew Seeley, president of the Migration Policy Institute in Washington, said additional deportations will require shelter, transportation, identification documents, job fairs and mental health resources.

"The Mexican government (does) . . . need to be ready in the next six months," he said, adding that it needed to "find ways to integrate immigrants from other countries into Mexico."