"We're not prepared to compromise on this and we believe that we stand on very firm legal and constitutional grounds," Wheeler said.
The tension between cities and President Trump over immigration policy reached a critical point on Wednesday as Trump, for the first time while in office, reiterated threats to pull federal funding if the cities won't comply with his administration's deportation plans. Trump also said in an ABC interview that he would start to build the border wall with Mexico which he promised on the campaign trail as soon as physically possible, within months.
The cost to cities could be steep.
On the line in a small city like Somerville, Massachusetts is $6 million in federal funding. In San Francisco, the federal funding is $1.2 billion, and in Seattle nearly $80 million, according to information provided by the cities to CNBC.
Most of the federal funding Trump has threatened to cut goes to urban programs that support a variety of causes, Wheeler said.
"Look at what those federal dollars in Portland are going for. They're largely going to help indigent populations, people who are lower income, people on disabilities, and school kids. I can't believe that at the end of the day Republicans are actually going to plant that flag in the ground," the Portland mayor said.