"To be clear: We will NOT comply with Gavin Newsom's unconstitutional mask ban," DHS posted on X Monday morning.
The ban is a direct response to recent immigration raids in Los Angeles, where federal agents wore masks while making mass arrests. The bill was signed by Gov. Gavin Newsom Saturday and goes into effect in January.
The Democratic governor said the state is pushing back against the practice of masked agents without identification or badge numbers detaining people on the streets.
In a news release, DHS called the ban "unconstitutional" and claimed ICE officers are "facing a more than 1000% increase in assaults against them."
Trump administration officials have defended use of masks, saying immigration agents face strident and increasing harassment in public and online as they carry out enforcement in service of Trump's drive toward mass deportation. Obscuring their identities is necessary for the safety of the agents and their families, officials contend.
The Associated Press contributed to this report.