Donald Trump made good on the hardline immigration policies that defined much of his campaign today, signing executive orders that direct the construction of a border wall between the US and Mexico, withhold federal funding from sanctuary districts, boost the numbers of ICE officers and detention facilities, halt refugee admissions, and block arrivals from several majority-Muslim countries.

The orders set off a wave of alarm and anger in the immigrant and activist community, and also put pressure on the nearly 300 cities across the country that had previously vowed to maintain sanctuary status. While the term “sanctuary city” has no firm definition, it has been used to describe places that shield undocumented immigrants from deportation by discouraging cooperation between local law enforcement and federal immigration authorities. (For more on why this approach actually leads to safer cities, read this Mother Jones feature).

But despite Trump’s threats to “crack down” on sanctuary districts, many of the US’s biggest cities have doubled down on their promise to stand with immigrants, including Los Angeles, Philadelphia, Chicago and New York City.

NYC Speaker Melissa Mark-Viverito responds to President Trump’s executive order on immigration & sanctuary cities.

“Given that today’s [executive order] was simply a directive and did not even make clear if there were any significant funding streams that the Trump administration could cut off to Philadelphia, we have no plans to change our immigration policy at this time,” said a spokeswoman for Philadelphia Mayor Jim Kenney in a statement. In Los Angeles, City Council President Herb Wesson affirmed that “the city is going to continue to operate the way it operates,” and Mayor Eric Garcetti suggested LA leaders are willing to mount a legal challenge to Trump’s order.

But one of the most powerful rebukes came from boricua NYC City Council Speaker Melissa Mark-Viverito, who slammed Trump’s executive actions in a charged press conference. Speaking in both English and Spanish, she vowed to “defend those children that come over the border fearing for their lives.”

“I will defend the undocumented women or man that comes here looking for a better lifestyle for themselves so they can provide for their families back home. And that is the vast majority of immigrants here,” she affirmed.

She also got some shots in, calling Trump a “highly insecure individual” and labeling Wednesday “a terrible day for the United States of America.”

Watch her remarks below: