Esvin Fernando Arredondo reunites with his daughters at Los Angeles International Airport. Ringo H.W. Chiu/AP

As his long-lost son walked toward him in an airport terminal, a sobbing David Xol stretched out his arms, fell to one knee and embraced the boy for about three minutes, crying into his shoulder.

He had not held the child since May 2018, when border agents pulled then-7-year-old Byron away inside a detention facility. They were separated under President Donald Trump's zero-tolerance policy - the father deported to Guatemala, the son placed in a series of government facilities before ending up with a host family in Texas.

David Xol hugs his son Byron at the airport as they reunite after being separated in Los Angeles. Ringo H.W. Chiu/AP

Xol was one of nine parents who won the exceedingly rare chance to return to the US after being deported under family separation. They arrived Wednesday at Los Angeles International Airport to be reunited with children they hadn't seen in a year and a half or longer under the order of a federal judge who found the US government had unlawfully prevented them from seeking asylum.

After embracing, David stood and patted Byron, now 9, on the head. "He was small,” the father said. "He grew a lot.”

The reunion was a powerful reminder of the lasting effects of Trump's separation policy, even as attention and outrage has faded amid impeachment proceedings and tensions with Iran. But it also underscored the fact that hundreds, potentially thousands, of other parents and children are still apart nearly two years after the zero-tolerance policy on unauthorized border crossings took effect.

"They all kind of hit the lottery,” said Linda Dakin-Grimm, an attorney who represents one of the parents returning to the US "There are so many people out there who have been traumatized by the family separation policy whose pain is not going to be redressed.”

David Xol hugs his son Byron at the airport as they reunite after being separated in Los Angeles. Ringo H.W. Chiu/AP

More than 4,000 children are known to have been separated from their parents before and during the official start of zero tolerance in spring 2018. Under the policy, border agents charged parents en masse with illegally crossing the US-Mexico border, then placed their children in government facilities. The policy drew condemnation from around the world as stories emerged almost daily about screaming children, some as young as babies, forcibly taken away from parents.

In June 2018, US District Judge Dana Sabraw ordered the government to stop separating families and reunite parents and children.

Esvin Fernando Arredondo was also on the plane. The father from Guatemala was separated from one of his daughters, Andrea Arredondo - then 12 years old and now 13, after they turned themselves in on May 16, 2018, at a Texas crossing and sought asylum legally, according to his lawyer. Sabraw found that Arredondo had been deported after his order to the U.S. government not to remove any more parents separated from his children.

Andrea was separated from all family for about a month, living in a shelter as the government struggled to connect children with their parents because they lacked adequate tracking systems. She was finally reunited with her mother, who had turned herself in at the Texas crossing with the other two daughters four days earlier than her husband, on May 12, 2018.