Portland Mayor Ted Wheeler on Monday warned protesters camping at the Portland office of the federal Immigration and Customs Enforcement agency to disband before they are removed by police.

During a press conference at City Hall, Wheeler, flanked by Commissioner Chloe Eudaly, Chief Danielle Outlaw and Fire Marshal Nate Takara, said occupiers should "peacefully disengage."

The mayor said officials will post a camp sweep notice Monday evening. Protesters will have until Tuesday to leave voluntarily, according a city notice. The notice states that protesters who remain may be face citation or arrest for trespassing, illegal camping and building structures on public rights of way.

Authorities move to reopen ICE facility in Portland 89 Gallery: Authorities move to reopen ICE facility in Portland

Occupiers set up a makeshift camp five weeks ago at a building leased by ICE on Southwest Macadam Avenue and have been at the building around the clock since. They said their intention is to protest the Trump administration's policy of separating children and parents who are detained after border crossings and seek the abolishment of ICE.

The field office closed for days because protesters blocked its entrances. Several demonstrators were detained and charged with misdemeanors when federal police moved to reopen the building. Protesters carried on, with tensions between their ranks and federal officers flaring up on occasion.

Demonstrations came to a head last week, when members of the right-wing Patriot Prayer group came to the campsite and argued with protesters. Three demonstrators were arrested at the time for crossing police lines and preventing access to the building.

A faction of protesters left voluntarily Monday, Eudaly said. Wheeler encouraged others to follow suit.

Wheeler said he supports protesters' cause, but believes the camp-out demonstration is no longer "sustainable."

"To all demonstrators: I urge you to keep up this effort," Wheeler said. He added that he believes it is time to for protesters to "move on" and focus on changing immigration policy, rather than camping at the ICE field office.

Wheeler declined to answer reporters' questions about what would happen to protesters who do not leave voluntarily and what he considers an acceptable demonstration, saying he would not "answer hypotheticals."

Occupiers announced Monday that they cannot achieve their goal of abolishing ICE "using occupation as a tactic alone," according to a statement sent by Occupy ICE PDX.

"We need to diversify and evolve our tactics in order to level this many-tiered beast," the announcement said, adding that protesters intend to "decentralize the movement" and "transition" out of an occupation.

Occupy ICE PDX gave a conflicting message on Twitter. Following Wheeler's press conference, the group tweeted, "Camp consensus: We don't move until ICE is out of Portland and abolished."

A spokesman for the demonstration Monday evening said protesters would continue to "hold our ground," and called on others in the city to join them at the encampment.

"We are going to be here, we are not going anywhere until [the Trump administration's] zero tolerance policy is lifted, until the last child is reunited with their parents, until not another local family is separated by ICE," said Jacob Bureros.

He said a four-person Occupy ICE PDX committee working as liaisons with Portland City Hall earlier released an "autonomous statement" about decentralizing the movement, but a poll taken later at the encampment showed the majority of people there favored staying put. Bureros said avenues of negotiation with city hall closed when city officials informed them that there was no legal way to remove ICE from Portland.

"This movement started because we were tired of waiting for the politicians and the so-called leaders to fix this," Bureros said. "We were tired of waiting for the rigged system to bring this to a reasonable end. We needed to stand up and do this ourselves."

Portland police officers later escorted people through the encampment who posted notices of intent to "clear the unlawful campsite" starting Tuesday. Anyone who doesn't leave could be arrested or cited, the signs said.

Everton Bailey Jr. of The Oregonian/OregonLive contributed to this report.

-- Gordon R. Friedman

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