SACRAMENTO, Calif. — Nineteen states, including California, are suing over the Trump administration's effort to alter a federal agreement that limits how long immigrant children can be kept in detention.

California Attorney General Xavier Becerra said Monday the rule change puts children at risk. He's leading the lawsuit alongside Massachusetts Attorney General Maura Healey.

A decades-old agreement known as the Flores settlement says immigrant children must be kept in the least restrictive setting and generally shouldn't spend more than 20 days in detention. The Trump administration says it plans its own set of regulations that would allow longer detention of immigrant families.

A judge must OK the proposed changes in order to end the Flores agreement.

California also seeks to halt a Trump administration proposal that could deny green cards to immigrants using public benefits.