NENTON, Guatemala/WASHINGTON (Reuters) - Migrant children will receive more thorough medical checks after an 8-year-old Guatemalan boy died in U.S. custody this week, the U.S. government said on Wednesday, and his mother expressed grief and despair over his death.

FILE PHOTO: U.S. Customs and Border Protection (CBP) officials in San Diego County, U.S., are seen through a hole on the metallic border wall between United States and Mexico, photographed through the border wall in Tijuana, Mexico, Dec. 17, 2018. REUTERS/Mohammed Salem/File Photo

Felipe Gomez Alonzo, who died on Monday, and his father, Agustin, 47, came from the western municipality of Nenton in Huehuetenango province, Guatemalan Foreign Ministry spokeswoman Marta Larra said. The pair trekked to the Mexico-U.S. border, joining thousands of others who have left their remote area.

Gomez, belonged to a family of indigenous Maya, was the second child to die this month in U.S. custody after crossing from Mexico, following the Dec. 8 death of Jakelin Caal, a 7-year-old girl also from Guatemala.

“I’m sad and in despair over the death of my son,” the boy’s 32-year-old mother, Catarina Alonzo, told Reuters by phone from her home in the tiny village of Yalambojoch, speaking through a translator because of her limited Spanish.

The latest fatality prompted sharp criticism from some Democrats, and U.S. Department of Homeland Security Secretary Kirstjen Nielsen announced policy changes on Wednesday aimed at preventing future deaths of children in custody.

All children in Border Patrol custody have been given a “thorough medical screening,” and moving forward all children will receive “a more thorough hands on assessment” as soon as possible after being apprehended, whether or not the adult with them asks for one, Nielsen said in a statement.

Gomez’s parents, who speak a Maya language called Chuj and little Spanish, have requested an autopsy be done as quickly as possible so their son’s body can be repatriated to Guatemala, Larra said. The results are expected in about a week, she added.

The U.S. Customs and Border Protection (CBP) agency has not released an official cause of death.

Most families in Nenton, a mountainous area near the Mexican border, are of indigenous origin and subsist on corn and beans, as well as money sent back from relatives working in the United States and Mexico, according to a local government report.

Huehuetenango sends the highest number of migrants abroad from Guatemala every year, Larra at the foreign ministry said.

Nielsen said the death of migrant children in U.S. custody is rare, noting that in the fiscal year ending Sept. 30, six migrants died under the CBP’s auspices, none of whom were children. It had been more than a decade since a child died in CBP custody, she added.

“It is now clear that migrants, particularly children, are increasingly facing medical challenges and harboring illness caused by their long and dangerous journey,” Nielsen said, noting she would travel to the border later this week to observe the medical screenings and conditions at Border Patrol stations.

She placed some blame for the risks faced by migrant children on their families. “Smugglers, traffickers, and their own parents put these minors at risk by embarking on the dangerous and arduous journey north,” Nielsen said.

INVESTIGATION DEMANDED

Gomez and his father were detained on Dec. 18 in El Paso, Texas, for illegally entering the country, the agency said.

They were given hot food, snacks, juice and water, and two days later, were transferred to the El Paso Border Patrol Station, CBP said. On Dec. 23, they were moved to the Alamogordo Border Patrol Station in New Mexico.

On the morning of Dec. 24, an agent noticed Gomez “was coughing and appeared to have glossy eyes,” CBP said, and the father and son were transferred to a nearby hospital.

The boy was found to have a fever and cold and was released with a prescription for an antibiotic and Ibuprofen. That evening, Gomez started vomiting, and his father declined medical help because his son had been feeling better, CBP said.

A few hours later, Gomez again began feeling nauseous and was taken back to the hospital, where he died just before midnight. CBP previously said he had died early on Tuesday.

U.S. House of Representatives Democratic leader Nancy Pelosi called on Wednesday for the DHS internal watchdog, the Inspector General’s office, to investigate Gomez’s death.

Other Democrats expressed outrage.

U.S. Representative Raul Ruiz of California said on a conference call that CBP facilities he had visited last week near El Paso were “dehumanizing” and not equipped to handle emergencies in remote areas of the Mexico-U.S. border.

“This is under the care and the responsibility and the custody of the United States government, and they do not meet the most minimal basic standards of humanitarian health,” he said.