(Reuters) - Over two hours on June 1, a Honduran teenager named Tania pleaded with a U.S. official not to be returned to Mexico.

Immigration authorities had allowed her mother and younger sisters into the United States two months earlier to pursue claims for asylum in U.S. immigration court. But they sent Tania back to Tijuana on her own, with no money and no place to stay.

The 18-year-old said she told the U.S. official she had seen people on the streets of Tijuana linked to the Honduran gang that had terrorized her family. She explained that she did not feel safe there.

After the interview, meant to assess her fear of return to Mexico, she hoped to be reunited with her family in California, she said. Instead, she was sent back to Mexico under a Trump administration policy called the Migrant Protection Protocols(MPP), which has forced more than 11,000 asylum seekers to wait on the Mexican side of the border for their U.S. court cases to be completed. That process can take months.

Tanias is not an unusual case. Once asylum seekers are ordered to wait in Mexico, their chances of getting that decision reversed on safety grounds - allowing them to wait out their proceedings in the United States - are exceedingly small, a Reuters analysis of U.S. immigration court data from the Executive Office for Immigration Review (EOIR) shows.

Many migrants and their advocates say they are vulnerable to violence in Mexican border cities, which have some of the highest homicide rates in the world facing dangers similar to those they fled in their home countries.

Of the 8,718 migrants in the program Reuters identified in the EOIR data, only 106 about 1% - had their cases transferred off the MPP court docket, allowing them to wait in the United States while their asylum claims are adjudicated.

The analysis, which provides the first public accounting of who is in the MPP program and how it is being carried out, comes as the program is set to be dramatically expanded. On Friday, Mexico agreed to implement it across the entire southern border to prevent U.S. President Donald Trump from imposing across-the-board tariffs on Mexican goods.

Trump, who ran for office on a platform of cracking down on illegal immigration, has grown increasingly frustrated by the ballooning numbers of mostly Central American families crossing the U.S.-Mexico border and asking for asylum in the United States. The administration devised the policy of returning asylum seekers to Mexico to reduce the number of migrants living in the United States while their cases chug through a backlogged court system.

Kathryn Mattingly, an EOIR spokeswoman, referred questions on the policy to the U.S. Department of Homeland Security (DHS). A DHS spokeswoman, who declined to be named, said the department could not comment on Reuters findings but said the program allows the United States to more effectively assist legitimate asylum-seekers and individuals fleeing persecution.

Many Central American migrants choose to travel through Mexico en route to the United States, so the great majority are likely not persecuted there, the U.S. government has said in court filings.

Immigrant rights groups have sued the administration to halt the policy. In April, a federal judge in California ruled it likely violated U.S. immigration law. In May, however, the 9th U.S. Circuit Court of Appeals allowed the program to continue while the legal challenge proceeds.

A HIGH BAR

Asylum seekers like Tania - who spoke on condition that only her first name be used because she feared for her safety inMexico can at any time tell U.S. officials they fear returning to Mexico, according to U.S. guidelines. That triggers an interview intended to ensure they are not returned to danger, in violation of U.S. and international law.

But the bar to pass these interviews is high: Migrants must prove they are more likely than not to face torture or persecution in Mexico.

In the pending litigation against the Trump administration, one appeals court judge said migrants might not know they have the right to ask for an interview about their fear of waiting inMexico. But the government responded in a court filing that asking every migrant if they fear persecution in Mexico would likely produce false claims that significantly slow down MPP processing and divert scarce resources.

Tania said that when she was separated from her family and first sent back to Mexico in April, she had no opportunity to express her fears. Instead, she said, she was put on a bus and driven across the border. It was only two months later, at her first hearing in immigration court, that she had the chance to tell a judge she was scared, she said. He then referred her to an interviewer.

U.S. Citizenship and Immigration Services, the division of DHS that oversees the officers that conduct these interviews, declined to say how many migrants plead fear of returning to Mexico and how many are allowed into the United States, citing the litigation.

Instead, Reuters analyzed EOIR data, which tracks every case registered with U.S. immigration courts and shows which are transferred off the MPP docket. When people are returned to Mexico they are given a notice to appear in immigration court, entering them in the system.

Reuters could not track people who may have been removed from the MPP program before their cases were registered with the court. For reasons that are unclear, the total of 8,718 MPP cases registered by June 5 falls somewhat short of the number of migrants that Mexican officials said had been sent back by then.

Immigration lawyers handling MPP cases in El Paso and SanDiego said the transfers are a good indication of how many people have been allowed in to wait in the United States, though they say some migrants likely were let in because they were pregnant, sick or otherwise deemed vulnerable - not because they passed a fear interview.

CARTELS AND CRIME

So far, most MPP migrants have been returned to Tijuana and Juarez, Mexican cities with high murder rates, where gangs and drug cartels operate and migrants often are kidnapped or robbed, they and their advocates say.

Returned migrants also say they struggle to find work, immigration lawyers and a permanent address where they can receive notice of their court hearings circumstances that fall far short of persecution but can affect their cases or ability to continue waiting. At least 106 immigrants in the program have been ordered deported in absentia, meaning they did not show upto hearings, Reuters found.

Authorities appear to have broad discretion in deciding who is placed in the MPP program. Tania was the only one in her family to be singled out. Her mother and younger sisters were allowed to wait in the United States, even as many other adults with children have been returned to Mexico.

More than 3,000 of those returned to Mexico are children, Reuters found, including 107 babies less than one year old.

DHS officials have said the policy would not apply to unaccompanied minors or Mexicans; however, the data shows 18Mexicans and one unaccompanied minor on the MPP court docket.

The MPP program includes more than 4,200 Guatemalans, 3,000Hondurans and 1,300 Salvadorans along with a handful of migrants from Peru, Ecuador, and Nicaragua, according to the EOIR data.

Reuters found the bulk of their individual asylum hearings have been set for this summer and fall, and a handful for later this year and early 2020.

Tanias individual hearing has yet to be scheduled.