TUCSON, Ariz. — The U.S. government has halted flights home for Mexicans caught entering the country illegally in the deadly summer heat of Arizona's deserts, a money-saving move that follows a seven-year experiment that cost taxpayers nearly $100 million.

More than 125,000 passengers were flown deep into Mexico for free since 2004 in an effort that initially met with skepticism from Mexican government officials and migrants, but was gradually embraced as a way to help people back on their feet and save lives.

The Border Patrol hailed it as a way to discourage people from trying their luck again, and it appears to have kept many away – at least for a short time.

But with Border Patrol arrests at 40-year lows and fresh evidence suggesting more people may be heading south of the border than north, officials struggled to fill the planes and found costs more difficult to justify. Flights carrying up to 146 people were cut to once from twice daily last year.

And this summer, there haven't been any.

The U.S. Department of Homeland Security, which includes the Border Patrol, said Monday that it anticipates flights will resume next month in a redesigned program.

A U.S. official who spoke on condition of anonymity because an agreement has not been reached said flights in the redesigned program would be for Mexicans arrested throughout the United States and run year-round. It would be designed for a mix of Mexicans who committed crimes in the United States and non-criminals.

"Removing Mexican nationals to the interior of Mexico is part of an effort to reduce repeat attempts to illegally enter the United States, avoid the loss of human life and minimize the potential for exploitation of illegal migrants by human smuggling and trafficking organizations as well as other organizations," the department said in a statement.

Mexico's Foreign Relations Department declined to comment Monday.

The flights had operated only in the summer and only in Arizona, designed as a humanitarian effort in response to the many migrants who have died over the last decade trekking through remote deserts in debilitating heat.

In an effort to keep the flights going with fewer migrants crossing, American authorities proposed mixing in Mexicans who commit crimes while living in the U.S.

"Everything comes down to dollars and cents," said George Allen, assistant chief of the Border Patrol's Tucson sector. "We're running into a more budget-conscious society, especially with the government."

He added, "Does it fit within our budget and is there an alternative that is not as effective but still effective?"

The Mexican government balked at seating hardened criminals next to families, elderly and the frail who recently crossed the border in search of work.

"Right off the bat, I can tell you that Mexico was not going to allow, nor will it ever allow, that kind of repatriation, which puts families' safety at risk," said Juan Manuel Calderon, the Mexican consul in Tucson.

U.S. and Mexican negotiators also discussed changing the route from El Paso, Texas, where many Mexicans with criminal records are held, to the central Mexican state of Guanajuato. In the past, the route has been from Tucson, Ariz., to Mexico City.

U.S. Homeland Security Janet Napolitano and Mexico Interior Secretary Alejandro Poire said in February that they planned to launch a pilot program April 1 to fly migrants arrested while living in the United States deep into Mexico. The pilot program was partly a response to complaints from Mexican border cities that too many deportees were being dumped on their streets and contributing to crime and unemployment.

"We wanted to maximize the flight and we couldn't come to an agreement," said Allen. "They were close. It may happen next year, but by the time it drug on, we got through July and for a short period of time, it wouldn't have been realistic."

The U.S. official who declined to be named said costs have been only one factor.

"The reason why (flights were halted this summer) is because we're still in negotiations with the government of Mexico," the official said.

The Mexican Interior Repatriation Program flights carried 125,164 passengers at a cost of $90.6 million since 2004, or an average of $724 each, according to U.S. Immigration and Customs Enforcement, which manages all flights for deportees.

The flights ran as few as 38 days in 2009 and as many as 120 days in 2010, when a record 23,384 passengers were flown. Last year, there were 8,893 passengers flown at a cost of $5 million – an average of $562 each.

The flights became a key piece of Border Patrol enforcement in Arizona as the agency moved to end its decades-old, revolving-door policy of taking migrants to the nearest border crossing to try again hours later.

The agency's new strategy, introduced in Tucson last year and later extended to the entire border, relies on tougher punishments that were rolled out in recent years. One calls for jail for up to six months and another one buses migrants to border cities hundreds of miles away to be deported there.

The one-way flights to Mexico City were aimed at first-time offenders and families. They were always voluntary and Allen said about 70 percent declined when they were introduced. But, as jail time and other punishments became more common, migrants increasingly jumped at the opportunity.

Without the flights, the Border Patrol is relying more on other punishments. It sends 70 people to federal court in downtown Tucson each weekday to face jail time. Deportation buses head east daily to Del Rio, Texas, and, when there are enough people to fill the seats, west to San Diego or Calexico, Calif.

Allen said Border Patrol data shows migrants who took the flights were less likely to be found again crossing the border illegally, though the agency has faced criticism for failing to release evidence of whether its tougher punishments are working.

In 2010, the Government Accountability Office said U.S. authorities had not shown the one-way flights were effective.

In Nogales, Mexico – about 60 miles south of the cavernous Border Patrol station in Tucson where most migrants arrested in Arizona are taken – more than a dozen deportees interviewed say they would accept a free flight home.

Juana Hernandez was dreading the two-day bus ride to her home in the central Mexican state of Michoacan and shared none of the Mexican government's objections to being seated alongside hardened criminals on a plane.

The flights appear to have discouraged migrants from crossing immediately after being deported but results over the long term were less clear.

Guillermo Martinez took a flight when he was deported a second time in 2010 but grew restless after an unsuccessful, two-year job search in his central Mexican state of Aguascalientes led to marital problems.

The Border Patrol arrested him in April with a group of 12 that agreed to pay a smuggler $1,500 each and spent nearly four months in an Arizona jail.

Martinez, who had only $17 in his pocket when he was deported last month, said he would accept another flight to Mexico City if it were offered and would try again to find a job back home.

Instead, he planned to stay in Nogales a couple months before trying to cross the border again, hoping to reach Atlanta, where his cousin promised a $12-an-hour job at a furniture factory. He dismissed the prospect of more jail time if he is arrested again.

"It would be lost time (in jail) but what do I have waiting for me if I return to Mexico?" he asked plaintively, sitting on back doorstep of a migrant shelter.

Also on HuffPost:

Loading Slideshow...
  • Amelia Reyes-Jimenez rides the bus to work in Zapopan, Mexico, Friday, Aug. 17, 2012. Reyes-Jimenez carried her blind and partly paralyzed baby boy, Cesar, across the Mexican border in 1995 seeking better medical care. She settled in Phoenix illegally and had three more children, all American citizens. In 2008 she was arrested after her disabled teen son was found home alone. Locked up in detention, clueless as to her rights or what was happening to her children, she pleaded guilty to child endangerment charges, and then spent two years trying to fight for her right to stay with her children. She lost and was deported back to Mexico without her children in 2010. (AP Photo/Dario Lopez-Mills)

  • This Aug. 14, 2012 photo shows Rony Molina holding a photo of his wife in his home in Stamford, Conn. Molina's wife, Sandra Payes Chacon, was deported to Guatemala in 2010, leaving Molina alone to care for their three children, all American citizens. (AP Photo/Jessica Hill)

  • Sandra Payes Chacon, wife of Rony Molina, poses for a portrait at a friends home in Atlixco, Mexico, Thursday, June 7, 2012. Sandra, who lived in the U.S. illegally, was deported to Guatemala a year and a half ago. She left behind her husband and her three children, all of them U.S. citizens. In the first six months of 2011, the United States removed more than 46,000 immigrants who were the parents of American-born children according to Immigration and Customs Enforcement (ICE). The number was first reported in a study called "Shattered Families" by the Applied Research Center, a New York-based social justice organization. Nearly 45,000 such parents were removed in the first six months of this year, according to the ICE. (AP Photo/Dario Lopez-Mills)

  • FILE - In this July 15, 2011 file photo, demonstrators hold signs in New York during a rally to condemn an immigration and customs enforcement program known as Secure Communities, and ICE's alleged refusal to meet with directly impacted immigrants. The signs read in Spanish "Deportations destroy our families." (AP Photo/Mary Altaffer, File)

  • Janna Hakim, 18, and her brother Sulaiman Hakim, 17, shows a picture of their mother Faten on Thursday, Aug. 16, 2012 in New York. On Aug. 13, 2010, Faten was taken away from home by ICE officials and deported to Ramallah, Palestine. (AP Photo/Bebeto Matthews)

  • In this March 1, 2012, children and their families take an adaptation course at the Binational Program for Migrant Education in the northern border city of Tijuana, Mexico. The program aims to ease the trauma of children who were deported from the United States and help them retake their studies in Mexico. In the foreground is Roxana Gomez from Guatemala, who is now studying the fourth grade at a primary school in Tijuana. (AP Photo/Alex Cossio)

  • In this photo taken April 23, 2012, a man who identified himself as Victor, left, sits on the stairs waits at the Casa del Migrante shelter for migrants, in Tijuana, Mexico. This haven for migrants that once sheltered mostly young people heading to America, full of hope, is now predominantly filled with men aged 30 to 40 years. Victor is staying at the shelter after he was deported from the U.S. and will try to cross back into the U.S. to reunite with his family. (AP Photo/Alex Cossio)

  • This undated photo provided by Felipe Montes via the Applied Research Center shows Montes and his wife, Marie Montes, and one of their three boys. When immigration agents deported Montes to Mexico two years ago, his three young sons _ American citizens _ were left in the care of their mentally ill, American-born mother. Within two weeks, social workers placed the boys in foster care. Montes and his wife want the children to live with him in Mexico, saying they are better off with their father than with strangers in the U.S. He works at a walnut farm and shares a house with his uncle, aunt and three nieces. But child welfare officials have asked a judge to strip Montes of his parental rights, arguing the children will have a better life here. Such a ruling could clear the way for their adoption. (AP Photo/Felipe Montes via the Applied Research Center)

  • In this Saturday, June 30, 2012, Juan C, 17, left, teaches his brother Miguel, 13, to box outside their home in Phoenix, Ariz. Juan was born in Michoacan and came to United States with his parents when he was 2-years-old. Flores who wants to become a professional boxer hopes to qualify for President Barack Obama Deferred Action program but he doesn't know if his charges for doing graffiti when he was younger will get in the way. Juan's father was deported five months ago and he has mixed feelings about applying for Obama's plan. (AP Photo/Nick Oza)

  • In this Tuesday, July 10, 2012 photo, Maria del Rosario Leyva, left, who returned with her 3-year-old boy and a 5-year-old girl from Santa Ana, California last year after their father, Marco Antonio Iglesias, right, was deported, try to get their children's U.S. birth certificates stamped by Mexican authorities in Malinalco, Mexico. Because of the Byzantine rules of Mexican and U.S. bureaucracies, tens of thousands of U.S. born children of Mexican migrant parents now find themselves without access to basic services in Mexico - unable to officially register in school or sign up for health care at public hospitals and clinics that give free check-ups and medicines. (AP Photo/Dario Lopez-Mills)

  • Norma Ramirez, center, in wheelchair, is embraced by her mother, Guillermina Clemente at the airport in Acapulco, Mexico, Monday April 16, 2012. Ramirez, an undocumented Mexican worker living in North Carolina who was facing an order of deportation, returned to her Mexico despite the fact that the Mexican consulate in Raleigh obtained a stay of her deportation order, when she learned she has terminal cancer and did not want to leave her U.S. born children alone in North Carolina. At left is the father of Ramirez, Margarito Ramirez Marquillo.(AP Photo/Bernandino Hernandez)

  • In this Dec. 20, 2010 photo, Lance Cpl. Aspar Andres speaks during a news conference concerning the deportation of his father, Juan Andres in Louisville, Ky. Family friend Jennifer Franklin sits at left. The Courier-Journal reports that Andres' 41-year-old father came here illegally from Guatemala as a teenager, more than 25 years ago. He was arrested recently after he accompanied a friend to a U.S. Immigration and Customs Enforcement office to act as a translator and it became apparent to an official there that he was in the country illegally. (AP Photo/The Courier-Journal, Frankie Steele) NO SALES; MAGS OUT; NO ARCHIVE; MANDATORY CREDIT

  • Al Okere, a 21-year-old college student at Central Washington University, walks out of his dorm building in Ellensburg, Wash., Thursday, Feb. 2, 2012. Okere, whose father was gunned down by police in Nigeria and whose mother was deported and now lives in hiding after losing her asylum plea, is hoping to avoid deportation himself. (AP Photo/Brian Myrick)

  • In this Jan. 4, 2012 photo, Jesus Gerardo Noriega, front, poses with his parents and brothers at the family home in Aurora, Colo. Jesus, 21, faced deportation last year after he was arrested for driving with no license plate light. Noriega's family brought him to the United States from Mexico when he was 9. His parents and three brothers live here legally, and he graduated from high school here. He learned in December that the case against him was being closed. He is pictured with brother Brian, mother Aracely, father Ricardo, and brothers Erick and Ricardo Jr. (AP Photo/Ed Andrieski)

  • In this Jan. 19, 2010 photo, Emilio Maya, left, tries to explain his complicated immigration situation to a relative in Argentina over the internet while his father, Emilio Maya, looks on at the Tango Cafe in Saugerties, N.Y. There was a time, when Emilio and Analia Maya's little Main Street cafe thrived and their dream of life in America seemed within reach. The brother and sister had settled in this picturesque village; he joined the volunteer fire department, she translated for the police. But they'd overstayed visitor visas and wanted desperately to fix their undocumented status. How? They made a deal with the department of Immigration and Customs Enforcement. In return for undercover tasks, they'd get work permits and eventually a special visa, they say agents promised. Years of clandestine assignments followed, a late-night stakeout at a house of prostitution and similar risky work. Then something changed. Emilio was seized by agents, including his handlers, and jailed to await deportation next month. His sister faces a hearing, too. (AP Photo/Seth Wenig)

  • Immigrants Fernando Miguel, right, with his father Rafael Miguel from Mexico, get help with documents and filling for the Deferred Action Childhood Arrivals applications at Casa de Maryland in Langley Park, Md., on Wednesday Aug. 15, 2012. Thousands of young undocumented immigrants lined up hoping for the right to work legally in America without being deported. The Obama administration's Deferred Action for Childhood Arrivals could expand the rights of more than 1 million young undocumented immigrants by giving them work permits, though they would not obtain legal residency here or a path to citizenship. (AP Photo/Jose Luis Magana)

  • Mexican citizen Elvira Arellano (L), a deported undocumented immigrant who spent a year living inside a Chicago church to avoid being separated from her US-born son, Guatemalan undocumented immigrant Mynor Montufar (R), the father of Rhode Island's first baby of 2008 and his Puerto Rican wife Carmen Marrero (C), are seen prior to the beginning of a meeting organized by the Guatemalan Congress' Migrant Commission on April 14, 2008 in Guatemala City. Mexican and Guatemalan congressmen are meeting to concur on joint actions to reach better treatment for migrants in the United States and the cessation of their deportations. EITAN ABRAMOVICH/AFP/Getty Images)

  • Daniela Pelaez

    In this Tuesday March 13, 2012 photo, Daniela Pelaez works on a school assignment at her home in Miami. Pelaez, who came to the United States from Colombia with her family when she was 4, is the valedictorian at the high school she attends and had been ordered to leave the country but will be allowed to stay for two more years after students at North Miami High School rallied around her, holding a protest and an online petition that collected thousands of signatures. (AP Photo/Wilfredo Lee)

  • FILE - In this Dec. 17, 2011 file photo, Tara Ammons Cohen reads with her son, Gavin, about a family friend in the local newspaper. Ammons Cohen was arrested in October 2008 on a drug charge and spent nearly three years locked up at the federal immigration detention center in Tacoma. She can'