SACRAMENTO – California sued the Trump administration Monday over a recently announced rule change that removes limits on how long the United States can hold immigrant children in immigration jails.

The lawsuit is California’s 57th against the administration and is joined by 18 other states including Massachusetts, New York and Pennsylvania. The coalition says the rule change announced last week endangers children and prevents states from being able to provide detained immigrant children with basic human needs.

California Attorney General Xavier Becerra claims the rule violates due process laws and the Administrative Procedure Act. Becerra has sued the administration over a variety of immigration matters, from border wall funding to a rule that makes it easier for the government to deny green cards to people who receive public assistance.

“The actions by this administration aren’t just morally reprehensible, as I said, they are illegal. Children don’t become subhuman simply because they are migrants,” Becerra said during a press conference Monday.

The lawsuit deals with a pending rule change that effectively ends the 1997 Flores settlement, which governs the treatment of immigrant children in immigration jails and was the result of a class action originally filed in California in 1983.

Flores requires detainees to be given bond hearings and be kept in “safe and sanitary” facilities, and sets timelines for how long children can be detained. More recently, court precedent has blocked the government from holding children for longer than 20 days – a limit the new rule would do away with.

The administration announced last week it was publishing a new rule that will remove the limits on how long the government can hold immigrant children. The new rule is due to take effect in less than two months.

Supporters of the change believe Flores had the unintended effect of encouraging people to try and cross the border with children in hopes of getting released before immigration proceedings.

Acting Department of Homeland Security Secretary Kevin McAleenan told reporters the change is meant to ensure that children are held with “dignity, respect and special concern,” and reduce overcrowding at immigration facilities.

Numerous scenes of children locked inside prison cells and otherwise miserable conditions at overcrowded facilities have gone viral and have been a major stain on the administration. At least seven children have died either in federal immigration custody or shortly after being released during Trump’s first term.

California Gov. Gavin Newsom called the administration’s treatment of detained children “perverse, unconscionable and clearly in violation of Flores.”

The first-term Democrat, who went to El Salvador in April to visit with the country’s political and business leaders, blasted Trump for nixing aid to Central American nations and ignoring what’s actually driving immigration to the U.S. He said the United States’ minimized role under Trump is allowing countries like China to “assert themselves” in the developing region.

“It’s extraordinarily frustrating that we’re here reacting in this moment, as opposed to more systemically addressing the root causes in a much more nuanced and sophisticated way. Those days seem to be over for the moment,” Newsom said of the administration’s immigration policies.

In the complaint filed in Los Angeles federal court, the coalition of states says the rule change is illegal because it overrides the states’ licensing requirements for facilities and would “result in the vast expansion of family detention centers, which are not state-licensed facilities and have historically caused increased trauma in children.”

Becerra also announced Monday that the state will ask for a preliminary injunction in its case against the administration’s plan to change the definition of “public charge” in order to deny green cards to people who receive public assistance. The lawsuit was filed two weeks and the District of Columbia and the states of Maine, Oregon and Pennsylvania have signed on as co-plaintiffs.