Nielsen says DHS can not detain children and parents together, so the only choice is to let families go free or detain them separately.
Sessions insisted children were well taken care of after they were indefinitely separated from their parents, and he told host Laura Ingraham the Department of Health and Human Services spent about $1 billion previous year taking care of children caught crossing the border.
He added that if parents are deported, their children will be permitted to leave with them, but if their parents claim asylum and are allowed to stay, the children stay also-in the custody of Health and Human Services.
"We do not want adults to bring children into this country illegally either placing those children at risk, but we do have a policy of prosecuting adults who flat our laws to come here illegally instead of waiting their turn or claiming asylym at any of our ports of entry", Sessions explained.
Sessions on Monday also confirmed that the new policy meant to send a "message" and deter people from "breaking across the border unlawfully"-just hours after Homeland Secretary Kirstjen Nielsen slammed that very notion". "We've had a big surge of families bringing children or some adults bringing children with them".
Democrats have turned up the pressure over the policy, and some Republicans have joined the chorus of criticism. Kansas GOP Senator Pat Roberts said he is "against using parental separation as a deterrent to illegal immigration".
Sen. Orrin Hatch, R-Utah, a former Senate Judiciary Committee chairman, also said Tuesday that he will send a letter to the Justice Department asking for a pause of family separation until Congress can pass a legislative solution. "Our Israeli partners know that better than anyone, and I was fortunate today to see the incredible work they are doing to keep their territory safe". Earlier this year Sessions announced a "zero-tolerance" policy that means all adults who cross the border illegally are being prosecuted, which means children can not be held with adults.
Trump has reportedly cited Israel's security barrier on the Egyptian border, and its success in blocking illegal immigration, as inspiration for his calls to build a wall on the Mexico border.
Ingraham played a clip of Hillary Clinton arguing that the separation of families is not "mandated by law", and asked if that was true.
He said immigration legislation set for votes in the House would end the practice.
Nielsen said that releasing parents with their children amounts to a "get out of jail free card" policy for illegal immigrants.
The compromise bill shifts away from the nation's longtime preference for family immigration to a new system that prioritizes entry based on merits and skills.