Sen. Dianne Feinstein Dianne Emiel FeinsteinBiden leads Trump by 12 points among Catholic voters: poll Names to watch as Trump picks Ginsburg replacement on Supreme Court McConnell says Trump nominee to replace Ginsburg will get Senate vote MORE (D-Calif.) plans to introduce legislation to prevent the separation of immigrant children from their parents at the U.S.-Mexico border, as the Trump administration is facing deep scrutiny over its policy.

"It’s hard to conceive of a policy more horrific than intentionally separating children from their parents as a form of punishment. ... This is not what the United States of America should be," Feinstein said in a Thursday statement.

She added that she is working on legislation to "prevent the intentional separation of families. Congress has a moral obligation to take a stand here.”

ADVERTISEMENT

Feinstein, who is up for reelection in November and is facing a primary challenge from the left, did not say when she would introduce the bill. The Senate is currently out of town until Monday afternoon.

The forthcoming legislation comes as a fight over the Trump administration's immigration policies is heating up.

The Department of Homeland Security is for the first time prosecuting people who are caught crossing the border illegally, a crime that’s been on the books since 1986.

But the Trump administration is trying to shift the blame to Democrats, arguing they are to blame for creating "loopholes" that leave border authorities no choice but to separate children from parents who are facing criminal charges.

Attorney General Jeff Sessions Jefferson (Jeff) Beauregard SessionsGOP set to release controversial Biden report Trump's policies on refugees are as simple as ABCs Ocasio-Cortez, Velázquez call for convention to decide Puerto Rico status MORE announced a "zero tolerance" policy last month for immigrants illegally crossing the Southwest border.

"If you cross the border unlawfully, then we will prosecute you. It’s that simple,” Sessions said earlier this month at a press conference at the U.S.-Mexico border near San Diego. “If you are smuggling a child, then we will prosecute you. And that child may be separated from you, as required by law."

He added in a statement: “To those who wish to challenge the Trump Administration’s commitment to public safety, national security, and the rule of law, I warn you: illegally entering this country will not be rewarded, but will instead be met with the full prosecutorial powers of the Department of Justice.”

But Democrats have panned the policy, arguing it isn't humane and punishes immigrants trying to seek asylum in the United States.

Feinstein added on Thursday that "these terrible policies call into question whether we are in violation of our own laws and our obligations under international law."