New York (AFP) – New York's governor on Thursday ordered federal immigration agents operating in her state to not wear masks, a move likely to be challenged by President Donald Trump's administration after courts overturned a similar effort in California.

Since the beginning of Trump's controversial mass deportation campaign, agents from Immigration and Customs Enforcement (ICE) have typically covered their faces, officially to avoid being identified and potentially threatened outside of work.

"For ICE, wearing masks without good cause is nothing short of an intimidation tactic, a cowardly attempt to evade responsibility," New York Governor Kathy Hochul, a leading Democrat opponent of Trump and his immigration policies, said Thursday.

Images of heavily armed, masked, plainclothes officers marauding around US cities including Minneapolis brutalizing citizens and non-citizens alike garnered international attention earlier this year, peaking when ICE officers shot dead two Americans in the Midwestern city.

As well as the restriction on face coverings, Hochul announced that ICE agents would no longer be permitted to enter schools, libraries, community centers, polling sites, and other sensitive locations without a judicial warrant.

She also forbade local police from cooperating with the agency in any operation conducted solely on immigration grounds.

"Our officers, paid for by local taxpayer dollars, were hired to protect their communities...they're not there to do the federal government's bidding," the governor added.

Trump's immigration pointman Tom Homan recently warned that "what's going to happen with places like New York, and (if) people pass ridiculous legislation not to work with us, we're going to flood the zone."

A law passed by California's legislature requiring federal agents to show their faces was blocked by a district court earlier this year, with an appellate court later also ruling against the measure.