"Somehow we've conflated everything, but there's two separate issues: 10,000 of those now in custody were sent by their parents, with strangers, to undertake a completely risky and deadly travel across the desert alone", Nielsen said in response.
Some, like MSNBC host Joe Scarborough, blasted the Trump administration for its conduct, but in her response on Monday, Nielsen suggested that not everyone who appeared as a family unit was, in fact, one. While Sessions didn't say "we have a new policy of separating families at the border", he did say "if you are smuggling a child, then we will prosecute you and that child will be separated from you as required by law", which results in families being separated at the border.
The family separation issue has emerged as one of the most inflammatory issues in a legislative fight to pass immigration reform. Former First Lady Laura Bush, in a Washington Post op-ed, wrote that "this zero-tolerance policy is cruel".
In her Tweetstorm, Nielsen says applying for asylum isn't illegal, but she conveniently left out a couple things.
In other instances, pediatricians and child advocates have reported seeing toddlers crying inconsolably for their mothers at shelters where staff are prohibited from physically comforting them.
Trump has placed blame for the policy on Democrats as recently as Friday, when he had an impromptu press conference outside the White House.
2,000 families separated at United States border in six weeks
On Twitter , many criticised Mr Sessions' citing of the verse given its historical use to justify slavery. The debate around Romans 13 dates back even further.
At an earlier event Monday, Nielsen said the White House would not apologize for the policy. And she said the children taken away from parents are doing fine.
The US separated about 1995 children from their parents and detained them between mid-April and May 31, according to the Office of Refugee Resettlement at the Department of Health and Human Services, which is responsible for their care.
Dr. Colleen Kraft, the president of the American Academy of Pediatrics, on Monday told "CBS This Morning" the separation of families at the border amounts to a "form of child abuse". "It could take place quickly". It is historic, with some countries the most unsafe places in the world. This administration has a simple message: "If you cross the border illegally, we will prosecute you", she added.
After a tour of the border facilities, Merkley and Van Hollen described in an interview with CNN "large pens of chainlink fences" holding about 1,500 migrant children and parents separated from their children after fleeing violence in Central America.
Previously, families crossing the border together would normally be released into the USA with an order to appear in immigration court.