Thousands of Central American migrants hoping to settle in the United States have given up and accepted free rides home paid for by the government.

The 'Assisted Voluntary Return' program has paid for buses or flights for 2,170 migrants according to Christopher Gascon, a U.N. International Organization for Migration (IOM) official.

Those taking the plan either never reached the United States or were detained after crossing the border and then sent to Mexico to await immigration hearings.

The $1.65 million program, funded by the U.S. State Department, was launched 10-months-ago but could raise issues over those seeking asylum.

Immigration advocates fear it could violate a principle under international law of returning asylum seekers to countries where they could face persecution.

More than 2,000 Central Americans have taken the return flight or bus route home instead of having their immigration case seen before a court in Mexico. Trump called the migrant caravans (above) an 'invasion' in the past

The graph (above) shows where people are returning to from Mexico after taking the free flight or bus ride home

Central Americans heading to the United States border in April this year as part of a migration caravan. They were pictured taken a break near Huehuetan, Chiapas state in Mexico

While the returned migrants have not been interviewed by U.S. asylum officers, the IOM screens all participants to ensure they are not seeking asylum and want to go back.

Gascon, head of the IOM's Mexico mission, said the program provides a safer and more humane means of return than the migrants could arrange on their own.

The effort, whose scope and controversial aspects have not been previously reported, is the first by the State Department and UN to target Central American migrants in Mexico on such a large scale. The State Department would not comment on the record about its role.

Gascon said the State Department reached out to the IOM last year as caravans of thousands of Central American migrants traveled through Mexico toward the U.S. border.

U.S. President Donald Trump called the caravans an 'invasion' and has made stemming immigration a centerpiece of his administration and 2020 re-election campaign.

Migrant advocates are particularly concerned about 347 people returned by the IOM who had been stuck in Mexico under a controversial Trump administration policy known as the Migrant Protection Protocols (MPP).

Under that policy, which began January 29, some migrants who make it across the U.S.-Mexico border are given a notice to appear in U.S. immigration court.

Many migrants who try to cross the border (above) are scheduled for an U.S. Immigration Court appearance

Now it's feared that those taking the return ticket back may not appreciate the damage it could cause to their chance of ever getting U.S. settlement rights

They are then turned back to Mexico to wait the months it can take for their court cases to be resolved.

In the past seven months, more than 30,000 migrants have been sent back under MPP, according to U.S. Customs and Border Protection.

Advocates say that the migrants often face danger and destitution in Mexican border towns, leaving them no good options.

'How can it be a voluntary decision (to return home) given the conditions they face in Mexico? It's a choice between two hells,' said Nicolas Palazzo, an attorney with El Paso-based Las Americas Immigrant Advocacy Center.

Besides any danger they might face back home, there is another significant downside to leaving: If migrants do not show up for a U.S. court hearing, they can be ordered deported 'in absentia,' reducing their odds of ever being granted refuge in the United States.

Denia Carranza, a 24-year-old Honduran and her seven-year-old son, returned to Mexico to await a court hearing set for October, decided instead to board a bus back home last week.

She explained that they were forced to flee their hometown and had hoped to apply for U.S. asylum.

Carranza left a good job at a shrimp packing company after gang members threatened to kill her if she did not deal drugs to fellow employees.

She was frightened of Ciudad Juarez, in Mexico - a battleground for drug cartels - where the bulk of migrants await their hearings. Also, she had no job and no way to provide for her son.

'I am scared of going back to Honduras. But I am more afraid to stay,' she said.

The United Nation's International Organization for Migration (IOM) have calculated stats upon surveying those leaving Mexico for the free ride

Shockingly many reported crimes they had suffered during their journey to try to settle in the U.S. Along with their time while awaiting a court date

The U.S.-based nonprofit Human Rights First said it had documented more than 100 violent incidents perpetrated against migrants waiting in Mexico for U.S. court hearings this year, including rape, kidnapping, robbery, assault and police extortion.

The IOM documented 247 deaths of migrants near the US-Mexico border this year through Aug. 15.

In a July 30 letter to the IOM's Director General, 30 U.S. and international advocacy organizations they expressed their fear of migrants 'out of desperation, not choice.'

It added: 'They may not fully understand the consequences of failing to appear whenever summoned by a U.S. immigration court.'

There is no way of knowing how many of the migrants who opt to go home with IOM help might have been able to present a successful asylum claim.

U.S. courts ultimately deny most such claims brought by Central Americans and the Trump administration has said many are fraudulent.

Migrants who are sent to Mexico under MPP may or may not be seeking U.S. asylum, but they generally have no opportunity to initiate such claims before being sent back across the border.

The policy cuts out a traditional asylum screening step in which migrants are interviewed to establish whether they have a 'credible fear' of returning home.

When the U.S. State Department approached IOM last fall, Gascon said, part of the goal was to counter what is saw as misinformation about how easy it was to get into the United States.

IOM set up kiosks at a stadium in Mexico City, which was along the caravan route, and on the U.S.-Mexico border. It also helped spread the word about free rides back in migrant shelters.

'When they saw the reality, some decided to go home,' he said of migrants.

The documents reveal the difficulties Central Americans face while awaiting their court dates, many of whom do not have shelter, food or work

The plan was introduced by the United States Government 10 months ago and cost $1.65 million. So far more than 2,100 have used the free return ride home

Three quarters of the migrants in the voluntary return program went back to Honduras, a fifth to El Salvador and the rest to Guatemala and Nicaragua, according to IOM figures through July 26 of this year.

More than half were 'family units' and about 100 were unaccompanied minors. Most of the migrants have been sent back from Mexico, and a small fraction from Guatemala.

The IOM screens all migrants who ask to go home, but those awaiting U.S. hearings in Mexico also undergo an orientation program with Grupo Beta, an arm of Mexico's National Migration Institute, to ensure migrants understand their options, Gascon said.

So far, Gascon said, two people awaiting U.S. court hearings in Mexico who wanted a ride back were instead referred to the Mexican government to gauge their eligibility for asylum in Mexico.

But advocates said they worried that Grupo Beta is not the best partner for IOM to ensure migrants' safety.

'Many organizations have documented time and again that Mexican migration officials don't refer people to (the national refugee office), they don't register fears of return, and they have even pressured people to withdraw (asylum) claims,' said Kennji Kizuka, a researcher at the nonprofit Human Rights First.

Mexican migration officials did not respond to a request for comment.

More than a dozen migrants awaiting U.S. hearings at the Casa de Migrante shelter in Ciudad Juarez told Reuters the weekly south-bound bus rides held some appeal. Though reluctant to give up on their American dreams, many didn't have lawyers and saw little prospect for success.

'All that effort we made to get here from Honduras and now we're going back,' said Angel Estrada, who had hoped to get care in the United States for his 9-year-old son, who has hemophilia. 'It's really sad.'