The Trump administration will start sending Mexican asylum seekers to Guatemala under an agreement brokered last year, a move that blindsided Mexican officials and will make it more difficult for Mexicans to seek protection in the US from violence and persecution.

Mexicans are now arriving at the US border in greater numbers than those from Central America’s “Northern Triangle” of Guatemala, Honduras, and El Salvador. Since October, almost 33,000 Mexicans have been apprehended at the southern border compared to about 11,900 Guatemalans, 9,900 Hondurans, and 4,500 Salvadorans.

But many of Trump’s policies, such as requiring asylum applicants to wait in Mexico while their cases are processed, don’t apply to Mexican citizens, who cannot be legally sent back to their home country if they would likely face persecution there.

A Department of Homeland Security spokesperson confirmed that certain Mexicans are now subject to the agreement the US and Guatemala reached in July, under which 97 Salvadorans and Hondurans seeking asylum in the US have already been sent to Guatemala. BuzzFeed reported that, according to internal agency emails, only those who specifically state that they fear persecution in Guatemala will have the opportunity to seek asylum in the US instead.

The Trump administration has claimed that migrants subject to the agreement will be able to seek asylum protection in Guatemala, but immigrant advocates say there’s reason to doubt that. Guatemala is not only producing large numbers of asylum seekers arriving at the US border, it also lacks the capability to receive asylum seekers en masse.

It’s not clear that Guatemala has even formally agreed to receive Mexican asylum seekers. On Wednesday, Guatemalan President Jimmy Morales told reporters that his government had not signed any such agreement, dismissing it as a rumor.

But if it does cover Mexicans as the US claims, the agreement would create an impossible choice for asylum seekers: They can either go to Guatemala despite the risks, or decide not to seek asylum at all and return to their home country — where they may have to face the same persecution that caused them to flee in the first place.

Mexicans claiming asylum are typically victims of cartel violence and extortion or have been targeted based on their indigenous heritage. The most recent waves of Mexican asylum seekers have come from the southern states of Chiapas, Oaxaca, Guerrero, and Michoacán, where cartel violence has spiked in recent months.

Foreign minister Marcelo Ebrard issued a statement Tuesday condemning the US’s decision to send Mexicans to Guatemala, estimating that it could affect as many as 900 asylum applicants by February. He said his office will be working to offer “better options” to Mexicans subject to the agreement, without specifying what an alternative might be.

Martha Bárcena Coqui, the Mexican ambassador to the US, told Mexican media on Tuesday that the government was not consulted on the US’s decision to start sending Mexicans to Guatemala under the agreement. Whether the US will be able to move forward will depend on whether Mexicans subject to the agreement decide to comply or return to their home country, she said.

”If Mexicans don’t want to go to Guatemala and prefer to return to their country, as we hope they do, the measure will stop by itself,” she said in Spanish.

How the agreement works

The US has brokered similar agreements with El Salvador and Honduras. Hundreds of thousands have fled violence and the lack of economic opportunity in the Northern Triangle over the past year.

The agreements with the Northern Triangle countries resemble “safe third country agreements” — a rarely used diplomatic tool that requires migrants to seek asylum in the countries they pass through by deeming those countries capable of offering them protection — although the Trump administration has been reluctant to use that term. Until recently, the US had this kind of agreement with just one country: Canada.

The administration has sought such agreements in Central America as a means of achieving President Donald Trump’s goal of driving down the number of migrants seeking refuge at the US southern border by sending them back to the countries they came from and passed through. But immigrant advocates argue that sending migrants back to those countries could have deadly consequences.

Only the agreement with Guatemala has gone into effect so far, though acting DHS Secretary Chad Wolf is traveling to Honduras this week to reportedly push for the implementation of that agreement by the end of the month.

A related rule published in November established a screening process to determine whether the US or Guatemala will process migrants’ claims for protection. Until now, only migrants from Honduras and El Salvador were subject to the Guatemalan agreement.

By expanding the scope of the agreement to include Mexicans, the Trump administration will make it harder for Mexicans to claim asylum in the US. DHS did not respond to requests for comment on when Mexicans would start being returned to Guatemala and why the scope of the asylum agreement was being expanded.

This isn’t the first step the administration has taken as the number of Mexican asylum seekers grows. In early October, the administration launched a secretive pilot program in El Paso specifically designed to decide Mexicans’ asylum cases quickly while they’re still in CBP custody.

In September, CBP also started subjecting more Mexicans to its practice of “metering,” under which it limits the number of migrants processed at ports of entry each day.

As a result, Mexicans who were previously being processed at the ports are now being turned away and forced to wait in the migrant camps on the Mexican side of the border, where migrant shelters are already at capacity. Sending Mexicans to Guatemala is just another tool in the administration’s arsenal to keep them out of the US.

Guatemala doesn’t have the capacity to accept asylum seekers

Though the US and United Nations agencies have been working for years to improve Guatemala’s asylum system, it’s still far from able to guarantee full and fair immigration proceedings to asylum seekers.

Guatemala’s asylum processing agency has less than 10 people on staff who have received only about 92 cases a year since 2015, according to Human Rights First. So far, only six of the migrants sent back to Guatemala under the agreement applied for asylum there and five others abandoned their claims, the LA Times reported.

Joaquin Castro, chairman of the Congressional Hispanic Caucus, said in a statement Tuesday that the Trump administration’s decision to start sending Mexicans to Guatemala is a “cruel and illegal effort” to “discourage families from seeking asylum in the US.”

“Let’s be clear: Guatemala is not a ‘safe third country,’” he said. “Their government is in no way prepared to take on the thousands of asylum seekers at our border who may be subject to this expanded agreement.”

According to the most recently available data from the United Nations, Guatemala had the ninth-highest homicide rate worldwide, about 26 deaths per 100,000 inhabitants. The State Department has issued travel warnings for US citizens in all four countries.

The Northern Triangle countries also produce high numbers of people seeking asylum. In 2017, the most recent year for which asylum information is available, the US granted asylum to 3,471 migrants from El Salvador, 2,954 from Guatemala, and 2,048 from Honduras.

Douglas Stephens, a former asylum officer who has spoken out against other Trump administration immigration policies, told reporters on Monday that the agreements are one of many Trump administration policies “designed to destroy” the US asylum program and to “target and discriminate against a particular class of would-be asylum seekers.”