MCALLEN, TX - JUNE 11:  Central American immigrants depart ICE custody, pending future immigration court hearings on June 11, 2018 in McAllen, Texas. Thousands of undocumented immigrants continue to cross into the U.S., despite the Trump administration's recent "zero tolerance" approach to immigration policy.  (Photo by John Moore/Getty Images)
John Moore/Getty Images
MCALLEN, TX - JUNE 11: Central American immigrants depart ICE custody, pending future immigration court hearings on June 11, 2018 in McAllen, Texas. Thousands of undocumented immigrants continue to cross into the U.S., despite the Trump administration's recent "zero tolerance" approach to immigration policy. (Photo by John Moore/Getty Images)
Now playing
01:05
Doctor: Family separation is child abuse
CNN
Now playing
01:23
Senator: Family separation is kidnapping
SAN DIEGO, CA - JULY 16:  An American flag flies along a section of the U.S.-Mexico border fence on July 16, 2018 in San Diego, California. The entire Southwest border saw 34,114 U.S. Border Patrol apprehensions in the month of June compared with 40,338 in May.  (Photo by Mario Tama/Getty Images)
Mario Tama/Getty Images North America/Getty Images
SAN DIEGO, CA - JULY 16: An American flag flies along a section of the U.S.-Mexico border fence on July 16, 2018 in San Diego, California. The entire Southwest border saw 34,114 U.S. Border Patrol apprehensions in the month of June compared with 40,338 in May. (Photo by Mario Tama/Getty Images)
Now playing
03:57
Hear: Immigrant moms plead with judge for kids
U.S. Border Patrol agents take a father and son from Honduras into custody near the U.S.-Mexico border on June 12, 2018 near Mission, Texas. The asylum seekers were then sent to a U.S. Customs and Border Protection (CBP) processing center for possible separation. U.S. border authorities are executing the Trump administration's zero tolerance policy towards undocumented immigrants. U.S. Attorney General Jeff Sessions also said that domestic and gang violence in immigrants' country of origin would no longer qualify them for political-asylum status. John Moore/Getty Images
John Moore/Getty Images
U.S. Border Patrol agents take a father and son from Honduras into custody near the U.S.-Mexico border on June 12, 2018 near Mission, Texas. The asylum seekers were then sent to a U.S. Customs and Border Protection (CBP) processing center for possible separation. U.S. border authorities are executing the Trump administration's zero tolerance policy towards undocumented immigrants. U.S. Attorney General Jeff Sessions also said that domestic and gang violence in immigrants' country of origin would no longer qualify them for political-asylum status. John Moore/Getty Images
Now playing
01:26
Parents of 71 children still unidentified
Now playing
01:48
You heard her cry for her mom. See their reunion
CNN
Now playing
01:34
Trump official: Separations are saving lives
Emanuella Grinberg/CNN
Now playing
03:16
Watch daughter wait for separated mom's arrival
U.S. Border Patrol agents take a father and son from Honduras into custody near the U.S.-Mexico border on June 12, 2018 near Mission, Texas. The asylum seekers were then sent to a U.S. Customs and Border Protection (CBP) processing center for possible separation. U.S. border authorities are executing the Trump administration's zero tolerance policy towards undocumented immigrants. U.S. Attorney General Jeff Sessions also said that domestic and gang violence in immigrants' country of origin would no longer qualify them for political-asylum status. John Moore/Getty Images
John Moore/Getty Images
U.S. Border Patrol agents take a father and son from Honduras into custody near the U.S.-Mexico border on June 12, 2018 near Mission, Texas. The asylum seekers were then sent to a U.S. Customs and Border Protection (CBP) processing center for possible separation. U.S. border authorities are executing the Trump administration's zero tolerance policy towards undocumented immigrants. U.S. Attorney General Jeff Sessions also said that domestic and gang violence in immigrants' country of origin would no longer qualify them for political-asylum status. John Moore/Getty Images
Now playing
00:57
Most toddlers still separated from families
Young migrant children, whose faces can not be shown, are seen at the US Customs and Border Protection Facility in Tucson, Arizona during a visit by US First Lady Melania Trump, June 28, 2018. (Photo by MANDEL NGAN / AFP)        (Photo credit should read MANDEL NGAN/AFP/Getty Images)
MANDEL NGAN/AFP/AFP/Getty Images
Young migrant children, whose faces can not be shown, are seen at the US Customs and Border Protection Facility in Tucson, Arizona during a visit by US First Lady Melania Trump, June 28, 2018. (Photo by MANDEL NGAN / AFP) (Photo credit should read MANDEL NGAN/AFP/Getty Images)
Now playing
01:44
Only 54 children to be reunited by deadline
BROWNSVILLE, TX - JUNE 22:  A crying  Honduran woman and her child wait along the border bridge after being denied into the Texas city of Brownsville which has become dependent on the daily crossing into and out of Mexico on June 22, 2018 in Brownsville, Texas. Immigration has once again been put in the spotlight as Democrats and Republicans spar over the detention of children and families seeking asylum at the border. Before President Donald Trump signed an executive order Wednesday that halts the practice of separating families who were seeking asylum, over 2,300 immigrant children had been separated from their parents in the  zero-tolerance policy for border crossers.  (Photo by Spencer Platt/Getty Images)
Spencer Platt/Getty Images North America/Getty Images
BROWNSVILLE, TX - JUNE 22: A crying Honduran woman and her child wait along the border bridge after being denied into the Texas city of Brownsville which has become dependent on the daily crossing into and out of Mexico on June 22, 2018 in Brownsville, Texas. Immigration has once again been put in the spotlight as Democrats and Republicans spar over the detention of children and families seeking asylum at the border. Before President Donald Trump signed an executive order Wednesday that halts the practice of separating families who were seeking asylum, over 2,300 immigrant children had been separated from their parents in the zero-tolerance policy for border crossers. (Photo by Spencer Platt/Getty Images)
Now playing
02:41
Hear emotional phone calls from parents separated from their kids
mother daughter reunion
mother daughter reunion
Now playing
02:12
Watch a mother and child reunite after 55 days
BROWNSVILLE, TX - JUNE 22:  A crying  Honduran woman and her child wait along the border bridge after being denied into the Texas city of Brownsville which has become dependent on the daily crossing into and out of Mexico on June 22, 2018 in Brownsville, Texas. Immigration has once again been put in the spotlight as Democrats and Republicans spar over the detention of children and families seeking asylum at the border. Before President Donald Trump signed an executive order Wednesday that halts the practice of separating families who were seeking asylum, over 2,300 immigrant children had been separated from their parents in the  zero-tolerance policy for border crossers.  (Photo by Spencer Platt/Getty Images)
Spencer Platt/Getty Images North America/Getty Images
BROWNSVILLE, TX - JUNE 22: A crying Honduran woman and her child wait along the border bridge after being denied into the Texas city of Brownsville which has become dependent on the daily crossing into and out of Mexico on June 22, 2018 in Brownsville, Texas. Immigration has once again been put in the spotlight as Democrats and Republicans spar over the detention of children and families seeking asylum at the border. Before President Donald Trump signed an executive order Wednesday that halts the practice of separating families who were seeking asylum, over 2,300 immigrant children had been separated from their parents in the zero-tolerance policy for border crossers. (Photo by Spencer Platt/Getty Images)
Now playing
02:02
HHS won't give exact number of kids in custody
CNN
Now playing
02:13
Berman: DNA test is de facto admission of no plan
CNN
Now playing
02:39
Doctor describes trauma of migrant children
CNN
Now playing
00:52
Mother reunited with her son after 32 days
CNN
Now playing
01:45
Immigration attorney represented 3-year-old
(CNN) —  

A 10-year-old Mexican girl with Down syndrome is among the thousands of children who have recently been separated from their parents at the southern US border, Mexico’s foreign minister said.

The girl and her brother were sent to a detention center in McAllen,Texas, and their mother was sent to a facility about an hour away in Brownsville after the family attempted to cross the border.

Foreign Minister Luis Videgaray said the Mexican consulate along with the girl’s father, a legal US resident, are working to get the girl released.

It’s a “particularly painful case,” Videgaray said.

The US Customs and Border Protection issued a statement saying the mother is not being prosecuted under the zero tolerance policy.

The mother and her five children were found June 3 in a vehicle driven by a US citizen, the statement said. The mother admitted to being in the US illegally, the statement said. Three of the children are US citizens and were released to an aunt, according to the statement.

“The mother was not prosecuted, but is instead being held as a material witness to support the prosecution of the smuggler, which precipitated the separation of the two other children, both Mexican citizens,” the statement said.

Federal agencies “are working to reunite the mother with her children as soon as possible,” the statement said.

The foreign minister said he was also aware of 21 Mexican children who have been separated from their parents. Most of the children have been sent back to Mexico but seven are still in US detention, he added.

At least 2,000 children have been separated from parents at the border as a result of the new “zero tolerance” policy, Department of Homeland Security officials said last week.

About 1% of the children detained at the US border were Mexican, Videgaray said, with the majority hailing from Guatemala, El Salvador and Honduras.

Videgaray condemned the practice, saying it was “cruel and inhumane.”

“The Mexican government in no way promotes illegal migration,” he said. “However, according to our constitutional principles and our convictions, we cannot be indifferent before an act that clearly represents a violation of human rights and that puts into a vulnerable position minors, children, including those with disabilities.”

The National Down Syndrome Society said it will work with authorities to help the girl.

“Our hearts and prayers go out to this child and her family during this unprecedented and trying time. NDSS will work with the appropriate authorities to ensure she receives all the resources from us that she needs to help comfort her until she can be reunited with her father and eventually her whole family, where she belongs,” the organization wrote on Facebook.

Corey Lewandowski, President Donald Trump’s former campaign manager, dismissed the story of the girl while appearing Tuesday on Fox News.

“Womp womp,” Lewandowski responded after former senior Democratic National Committee adviser Zac Petkanas mentioned the girl.

CNN’s Ray Sanchez contributed to this report.