The potential deployment in Portland -- the largest city in Oregon -- would follow similar moves by the Republican president to mobilize troops against the wishes of local Democratic leadership in Los Angeles and the capital Washington.

"At the request of Secretary of Homeland Security, Kristi Noem, I am directing Secretary of War, Pete Hegseth, to provide all necessary Troops to protect War ravaged Portland, and any of our ICE Facilities under siege from attack by Antifa, and other domestic terrorists," Trump wrote on his Truth Social platform.

"I am also authorizing Full Force, if necessary," he added, without specifying what "full force" meant.

Portland has seen months of protests at a local ICE facility amid anger over the Trump administration's crackdown on undocumented migrants.

The city was also the scene of major clashes during Trump's first term, at the height of racial justice protests following the May 2020 police killing of George Floyd.

Protests have occurred at other ICE facilities around the country as Trump's mass deportation drive has seen thousands of migrants rounded up, often by masked agents.

The hardline approach has sparked conflict with local so-called "sanctuary" jurisdictions like Portland, which have policies of not coordinating with federal immigration authorities.

Trump first deployed troops in Los Angeles in June, overriding the state's Democratic governor and prompting an ongoing legal dispute over the limits of presidential authority.

Trump's announcement Saturday comes days after a deadly shooting at an ICE facility in Texas, in which one detainee was killed and two severely injured.

Federal officials say the gunman, who died from a self-inflicted gunshot, had sought to target ICE agents from a nearby rooftop.

That shooting happened weeks after the killing of conservative activist Charlie Kirk at a university campus.

Following Kirk's death, Trump announced that he was labeling the diffuse left-wing "Antifa" movement as a "domestic terrorist group."

The designation has led to worries among Trump's critics that it could be used to broadly suppress dissent in the name of national security.

"We are witnessing domestic terrorist sedition against the federal government," Trump's top aide, Stephen Miller, wrote Friday evening on X.

"All necessary resources will be utilized," he added.