The Biden administration's Justice Department is threatening to sue the state of Oklahoma over a recently passed law that would criminalize illegal immigration at the state level.

The law, signed by Governor Kevin Stitt, allows law enforcement agents to arrest suspected illegal immigrants who may be guilty of "impermissible occupation" in Oklahoma, with varying penalties for first and second-time convictions, reports the Daily Wire.

In a letter to Governor Stitt, DOJ Principal Deputy Assistant Attorney Brian Boynton claimed that the law is unconstitutional and contrary to the goals of the Immigration and Nationality Act (INA).

“The United States intends to file suit to enjoin the enforcement of HB 4156 unless Oklahoma agrees to refrain from enforcing the law,” the letter reads. “The United States is committed to the processing of noncitizens consistent with the Immigration and Nationality Act (INA). HB 4156 is contrary to that goal.”

Oklahoma Attorney General Gentner Drummond responded, asserting the state's sovereign right to protect its citizens and criticizing the Biden administration for its handling of the border crisis.

Oklahoma is not alone in passing legislation to address the unprecedented crisis on the southern border. Iowa, Texas, and Georgia have also enacted laws aimed at curtailing illegal immigration, drawing criticism and legal threats from the federal government.

Texas has been involved in legal battles with the federal government over legislation allowing state officials to detain and charge illegal immigrants, as well as taking control of a park along the Rio Grande to prevent illegal entry.

Since President Biden took office, authorities have recorded over 9.5 million nationwide encounters with illegal immigrants and an estimated 1.7 million gotaways, compared to just 445,000 total reported gotaways during the Trump administration from 2018 to 2020. As a result, Biden's approval ratings on the issue have suffered, with polls indicating that only 20 percent of voters believe the U.S. has control over its borders, and a mere 36 percent approve of the president's handling of the crisis.