NEW YORK (CBSNewYork) -- Mayor Bill de Blasio on Wednesday said President Donald Trump's executive order stripping funding for sanctuary cities would be severely damaging to New York City.
Trump on Wednesday signed the order targeting sanctuary cities, which do not arrest or detain immigrants living in the U.S. illegally.
De Blasio said the loss of funds would cut the resources of the NYPD -- including anti-terrorism funding -- and damage relations between police officers and communities. He added that the city would not begin deporting law-abiding undocumented immigrants because of the order.
The lost funds would reduce the NYPD's resources to fight crime and terrorism and make the city less safe, not more, de Blasio said.
"The executive order on its face contradicts its stated purpose," de Blasio said.
Other cities would also be adversely affected, the mayor said.
"(There are) hundreds of American cities where this executive order could undermine public safety, create a rift and a disconnect between police and those they serve, and take away federal funding from law enforcement," de Blasio said.
But the mayor said in New York City, "this executive order does not change who we are or how we go about our work."
"This is a city of immigrants. We always have been for almost 400 years," de Blasio said. "This is our fundamental nature."
De Blasio said the city would go on defending all its people, "regardless of where they come from and regardless of their immigration status."
"We're a city in which people, regardless of their documentation status, know that they can report a crime, or if they're a victim of a crime they can come forward, if they're a witness to a crime they can come forward, and know that that information will be used to keep all of them safe and will not be used to deport them," de Blasio said.
The mayor also said the city would not allow the progress the NYPD has made in making New York City the nation's safest big city to be undermined.
He added that the executive order is written in a "very vague fashion," and expected that it would be susceptible to legal challenges and public resistance.
"There is less here than meets the eye," de Blasio said.
Regardless of what happens, de Blasio said, the values of New York City will not change.
"We will not deport law abiding New Yorkers. We will not tear families apart. We will not divide children from their parents. We will not take breadwinners from families with no one else," de Blasio said.
De Blasio appeared at a news conference Monday with police Commissioner James O'Neill, City Council Speaker Melissa Mark-Viverito, and other officials. Mark-Viverito slammed Trump's policies as "bigoted" and called him "delusional" for characterizing his orders as "immigration reform."
"New Yorkers know that immigrants contribute to our economy, our culture and our communities. Immigrants are our families, our friends, our coworkers and our neighbors," she said. "We're not going to stand idly by while the Trump administration tears families apart and uses them as scapegoats."
Also at the news conference, U.S. Rep. Joseph Crowley (D-N.Y.) said the order "scares the daylights" out of him – given that it would take away resources from law enforcement and could even leave New York vulnerable to a terrorist attack.
"It's going to shut down our ability of our law enforcement folks to get information from law-abiding individuals who want to expose the criminal elements" in their communities because those people will fear deportation, Crowley said.
"This is not the American way. This is not what we've been about over the last 75 years, and Donald Trump needs to hear it," Crowley said.
In announcing the crackdown, White House Press Secretary Sean Spicer accused sanctuary cities of flouting the law.
"We're going to strip federal grant money from the sanctuary states and cities that harbor illegal immigrants," Spicer said. "The American people are no longer going to have to be forced to subsidize this disregard for our laws."
Attorney General Eric Schneiderman said Trump does not have the constitutional authority to punish cities by withdrawing funding in such a fashion.
"The president lacks the constitutional authority to cut off funding to states and cities simply because they have lawfully acted to protect immigrant families," he said in a statement. "Any attempt to bully local governments into abandoning policies that have proven to keep our cities safe is not only unconstitutional, but threatens the safety of our citizens."
"I urge President Trump to revoke this Executive Order right away. If he does not, I will do everything in my power to fight it," he added.
Trump on Wednesday also signed an executive order to jumpstart construction of a U.S.-Mexico border wall, one of his signature campaign promises.
Later in the week, Trump is expected to sign an executive order blocking Syrian refugees from entering the country, along with people from seven predominantly Muslim countries. No exact details have been released. But during the campaign he called it "extreme vetting."
Trump had backed off his original campaign proposal, calling for a temporary but complete ban on all Muslims from entering the U.S.
for more features.