The Department of Homeland Security reportedly warned three Democratic states that ignoring demands from the US Immigration and Customs Enforcement could trigger lawsuits and federal funding cuts.
Acting ICE Director Todd Lyons sent letters on Sept. 10 to the attorneys general of New York, California and Illinois, demanding they confirm whether their states will honor detainers placed on thousands of illegal immigrants or release them from custody, according to the Department of Homeland Security.
The federal agency said New York and Illinois refused to comply, while California did not respond.
Lyons responded in fiery letters Thursday, accusing the sanctuary states of "obstructing immigration enforcement" and threatened to have the Justice Department take legal action and block federal aid, according to the message's obtained by CBS News.
"ICE will engage with the U.S. Department of Justice and other federal partners to pursue all appropriate measures against you," Lyons wrote in his follow-up letter to Illinois Attorney General Kwame Raoul.
New York Attorney General Letitia James and California Attorney General Rob Bonta received similar warnings, the outlet reported.
Raoul initially responded to Lyons on Sept. 12, arguing that the federal government lacks the legal authority to demand state or local law enforcement to adhere to ICE detainers.
"Responding to an ICE detainer based on erroneous information could subject Illinois law enforcement agencies to liability for ICE's mistakes," Raoul's letter read, the outlet reported.
"And unfortunately, the number of erroneous detentions by ICE continues to grow at an alarming pace."
ICE has conducted large-scale enforcement operations in several major US cities, including the Big Apple, Chicago, Los Angeles and Washington, DC, as part of President Trump's directive on illegal immigration.
DHS Assistant Secretary Tricia McLaughlin on Saturday ripped each state's defiance, warning that releasing murderers, rapists, and pedophiles onto the streets will put residents in danger.
"These dangerous sanctuary policies, often combined with cashless bail for serious crimes, allow criminal illegal aliens to be released back into American communities - threatening the American people's lives and wellbeing," McLaughlin said in a statement.
"ICE detainers ask for something very simple: To notify ICE when criminal illegal aliens are released from jail or prison, to ensure that they go into ICE custody before they are released back onto our streets.
"These sanctuary state politicians should do the right thing and side with law-abiding Americans over criminal illegal aliens."
The three attorneys general did not immediately respond to The Post's request for comment.