A four-month-old baby was likely the youngest migrant child separated from their family by the Trump administration last year, according to The New York Times.

A recent episode of the newspaper's TV series "The Weekly" showed how the child was taken from his father at the US-Mexico border last year and spent five months in government custody.

Though the child, Constantin Mutu, was eventually reunited with his family, his parents say he's not the same. He is now 18 months old and cannot walk or speak.

President Donald Trump brushed aside criticisms of his administration's family separations, telling Telemundo in an interview that aired Thursday that he "brought families together."

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A four-month-old baby is likely the youngest migrant child separated from their family by the Trump administration last year, The New York Times reported.

In an episode of the newspaper's new TV series that aired on Hulu and FX on Sunday, reporter Caitlin Dickerson detailed her efforts to track down Constantin Mutu, who is now more than a year-and-a-half old and has been reunited with his parents in Romania.

The child was taken from his father at the US-Mexico border last year and was sent to live with a foster family in Michigan for five months while his father was detained and deported back to Romania.

The Mutus, seeking better lives for themselves in America, sold their home to pay a smuggler who would take them through Mexico to America, where they would request asylum, they told The Times.

But Constantin and his father, Vasile Mutu, ended up accidentally separated from their other family members on the journey, and ended up requesting asylum from US immigration officers alone.

"The police wiped the floor with me," Vasile Mutu told The Times through a translator, adding that the officers dragged him out of the room while leaving Constantin behind. "I started crying because I didn't know what to do. … I couldn't speak English. I told them, 'I don't understand. Why?'"

Thousands of children were separated by the Trump administration

Central American asylum seekers wait as U.S. Border Patrol agents take them into custody on June 12, 2018 near McAllen, Texas. Getty Images/John Moore

The Mutus' situation played out similarly to that of thousands of migrant families who crossed border illegally last spring. Under the Trump administration's "zero tolerance" policy, all adults caught crossing the border illegally were taken for criminal prosecution, thereby separating them from any children that had been traveling with them.

President Donald Trump addressed family separations in a Telemundo interview that aired Thursday, falsely accusing former President Barack Obama of implementing a family separation policy and denying that his own administration was responsible.

Read more: Trump says he 'brought the families together' after being confronted in an interview about migrant family separations

Trump also misleadingly took credit for reuniting the thousands of migrant families that were separated last year.

"When I became president, President Obama had a separation policy. I didn't have it. He had it," Trump said, inaccurately. "I brought the families together. I'm the one that put them together. Now I said something when I did that: 'Watch, many more people will come up,' and that's what happened."

Though Trump signed an executive order in June 2018 halting family separations under the "zero tolerance" policy, his administration did not reunite families until a federal judge ordered officials to begin doing so.

To this day, it's unknown exactly how many children were separated, though the number is in the thousands.

Experts warned that children like Constantin could suffer lasting harm from the separations

As for Constantin, his reunification with his family was nearly as traumatizing as his separation. He screamed and cried the entire drive back from the Romanian airport, devastated at the loss of his foster mother, The Times reported.

Pediatricians and mental-health experts had long warned that family separation would cause serious, lasting psychological damage to children like Constantin. Removing a caregiver from a young child's life can cause depression and post-traumatic stress disorder, which can be especially harmful to young children's developing brains.

Read more: Separating kids from parents at the border mirrors a 'textbook strategy' of domestic abuse, experts say — and causes irreversible, lifelong damage

Constantin's mother told The Times she struggled for weeks to get her son to eat and sleep, and often texted the foster mother for advice. Constantin is now 18 months old, and still can't walk on his own, and cannot speak.

"He says absolutely nothing," his mother said.