Dozens of Homeland Security agents and investigators will deploy to Guatemala as part of the Trump administration’s desperate attempt to slow unauthorized migration to the United States from Central America, according to U.S. officials with knowledge of the plans.

The Department of Homeland Security personnel will work as “advisers” to Guatemala’s national police and migration authorities, and they will aim to disrupt and interdict human smuggling operations, the officials said, speaking on the condition of anonymity to describe a plan that has not been made public. U.S. authorities hope that the effort will cut off popular routes to the United States and deter migrants from beginning their journeys north through Mexico.

Plans call for at least several dozen DHS agents and investigators, and one DHS official briefed on the plans said about 80 U.S. law enforcement personnel will deploy as part of the mission. Another DHS official said Immigration and Customs Enforcement will send 18 Homeland Security Investigations agents and intelligence analysts, along with six agents from the Enforcement and Removal Operations division.

Acting DHS secretary Kevin McAleenan has advocated the more muscular DHS presence and finalized the agreement with Guatemalan President Jimmy Morales and other top Guatemalan officials during meetings this week in Guatemala City.

“The U.S. and Guatemala are formalizing a number of initiatives to improve the lives and security of our respective citizens by combating human trafficking and the smuggling of illegal goods, helping to limit ‘push’ factors that encourage dangerous irregular migration to the U.S., perpetuating the ongoing crisis at our border,” McAleenan said in a statement, after signing a “Memorandum of Cooperation” with Guatemalan officials.

President Trump, who threatened Thursday to impose severe tariffs on Mexican imports if the country’s government doesn’t crack down on migration, has said he will cut off aid to Central America in an effort to pressure the region’s leaders.

But McAleenan has urged more — not less — cooperation with Central America, and his plan to assign personnel from U.S. Customs and Border Protection and Homeland Security Investigations to work alongside Guatemalan police amounts to an attempt to put more weight behind the approach.

According to DHS, the agreement allows for “concrete actions” including “law enforcement training and collaboration to improve criminal investigations.”

The U.S. agents probably would deploy to Guatemala and its border with Mexico for weeks at a time in an “advisory” role. U.S. security personnel assigned to Guatemala are typically authorized to carry weapons.

“Other areas of cooperation include increasing the security of the Guatemalan border to stem the flow of irregular migration while ensuring proper preparation to improve the ability of both countries to identify and better understand their root causes,” according to a DHS news release.

While the scale of the deployment and the location — the Guatemala-Mexico border — would be unusual, there are precedents for U.S. law enforcement presence in Central America. Armed Drug Enforcement Administration agents conduct operations in the region, and CBP advisers work with Mexican officials to improve immigration screening procedures and to upgrade technology.

One of the areas U.S. agents will target is the department of Huehuetenango in Guatemala’s destitute western highlands, where emigration levels are among the highest in the region.

Villages along the Pan-American Highway through Huehue­tenango have been emptying out, and in some places, residents say half the population has left for the United States in the past two years. Coffee fields have been abandoned. Many families have used their houses as collateral for the trip, taking out loans to pay their smugglers.

According to DHS officials, 3 percent of Huehuetenango’s entire population has left for the United States in the past seven months.

In the border city of La Mesilla, just south of the Mexican state of Chiapas, some migrants arrive at night at the local bus terminal, where they look for smugglers to hire. Nearby hotels — including the Texas Hotel, named for some of the migrants’ destination — cater to families on their way north. Many leave La Mesilla by truck and van, arriving at unmarked border crossings, not far from main highway corridors.

U.S. authorities have apprehended more than 100,000 migrants crossing the border from Mexico in each of the past three months, and unauthorized border crossings have soared to their highest level in at least 12 years. McAleenan told reporters Thursday that border agents are processing an average of 4,500 people each day, an increase of more than 30 percent since March, when he declared that U.S. agents and infrastructure had hit “the breaking point.”

In rural Guatemala, there is a widespread belief that bringing a child on the journey to the United States will make it easier to avoid detention and deportation. U.S. courts have limited the amount of time children can be held in immigration jails to 20 days, and because U.S. authorities can’t process their asylum claims that fast, the families are typically issued a court appointment and released into the U.S. interior.

“That’s the thing everyone knows now. If you go, you need to bring a child,” said Juan Vasquez, from La Libertad, who is considering migrating with his two daughters in coming weeks. “You can bring someone else’s child, but they say they are now doing DNA tests on the border, which make it difficult.”

Many Guatemalans say they have been told the ability to enter the United States with a child is part of an official U.S. policy that is due to expire in about a year; such rumors are often spread by smugglers trying to drum up business. “It’s something that they say is going to expire,” said Anselmo Torres, 58, also from La Libertad, whose two daughters migrated earlier this year with children of their own.

The United States has no such policy, but Trump last year ordered an end to family separations of migrants apprehended at the border after his “zero tolerance” crackdown triggered a ferocious backlash. He has since insisted the family separations would have worked as a deterrent if he had kept them in place.

At least nine people accused of human smuggling were arrested in Guatemala City on Wednesday, part of a joint operation between DHS and Guatemalan authorities, according to Guatemalan officials. It was the first such joint operation after the signing of the memorandum.

At the scene of the arrest, officials wearing jackets emblazoned with the acronym for “Homeland Security Investigations” — a division of U.S. Immigration and Customs Enforcement — were seen standing next to Guatemalan police officers.

U.S. Rep. Vicente Gonzalez (D-Tex.) said he met with Guatemala’s ambassador to the United States, Manuel Espina, and that Espina told him Guatemala would welcome U.S. troops to help secure its northern border. After the meeting, Gonzalez wrote a letter to President Trump, urging him to accept the offer. The letter, asking for the United States to send military personnel, was obtained by The Washington Post.

“Guatemalan president Jimmy Morales has indicated that he would welcome the introduction of U.S. troops on Guatemala’s northern border,” Gonzalez wrote on April 16. “If you want to see fewer apprehensions at the U.S.-Mexico border, I would strongly encourage you to seriously consider President Morales’ offer.”

Gonzalez said he believes sending 100 U.S. agents to Guatemala would be insufficient, and he would continue pushing to send U.S. military forces to Guatemala, with Morales’s approval, “on a humanitarian mission to help secure Guatemala’s border.”

Gonzalez said he did not receive a response from the White House.

Sieff reported from Huehuetenango, Guatemala, and Mexico City. Mary Beth Sheridan in Mexico City contributed to this report.