NEW YORK — New York City Mayor Bill de Blasio says he won't meet with Republican President Donald Trump to discuss infrastructure funding.

The Democrat originally was expected to attend a meeting with other mayors at the White House on Wednesday afternoon.

Instead, he blasted the Trump administration on Twitter, saying the Department of Justice had decided to renew a "racist assault" on immigrant communities.

De Blasio has been an outspoken critic of Trump.

I will NOT be attending today’s meeting at the White House after @realDonaldTrump’s Department of Justice decided to renew their racist assault on our immigrant communities. It doesn’t make us safer and it violates America’s core values. — Bill de Blasio (@NYCMayor) January 24, 2018

New Orleans Mayor Mitch Landrieu and other mayors had also been invited to the White House and declined the invitation because of a Justice Department crackdown on so-called sanctuary cities.

On Wednesday, the Justice Department escalated their fight against 23 so-called sanctuary cities, sending letters asking for greater compliance with federal immigration law.

Landrieu told reporters in Washington that he would not go to the meeting under "false pretenses," complaining that the meeting is supposed to focus on infrastructure but that the Justice Department's sanctuary cities move changed the equation.

"An attack on one of our cities' mayors who is following the Constitution is an attack on all of us. I will not be attending that meeting," he said.

At least the mayors of four cities that received Justice Department letters were meant to attend Wednesday's meeting: Michael Hancock of Denver, Greg Fischer of Louisville, Kentucky, and de Blasio.

"Our goal here is to ensure compliance with applicable federal law. Our goal is to ensure that jurisdictions that will comply with applicable federal law receive the the grant money and can keep the grant money that they have already obtained," a senior Justice Department official said about the letters.

Cities such as New York have sought to fight Trump's immigration policy, leading the administration to threaten to cut federal funding if they do not comply.

Despite their repeated attempts, courts have repeatedly blocked the Justice Department's attempts to crack down on the so-called sanctuary cities.

White House spokeswoman Lindsay Walters said before Landrieu and de Blasio declined to attend that the meeting was meant to focus on "the growing economy, as well as working together to tackle the opioid epidemic and rebuild the nation's aging infrastructure."

After they announced they would decline to attend, Walters said the White House was "disappointed" over their decision to "make a political stunt instead of participating in an important discussion with the President and his administration."

The "working session" between Trump and the mayors was slated to put leaders like Landrieu, de Blasio and Columbia, South Carolina's Stephen Benjamin in the same room with a man whom many of the mayors have used as a rhetorical foil for months, setting up the possibility for contentious exchanges.

Landrieu, whose term in New Orleans ends later this year, has been an outspoken critic of Trump, particularly on the way that he describes cities and his comments about Confederate monuments. Landrieu is among the Democrats rumored to be eying a presidential run in 2020.

The frequent criticism of Trump from mayors -- including Landrieu -- focus on the President's efforts to disparage American cities.

"Our cities are a source of American pride," Landrieu, who endorsed Hillary Clinton, wrote in an October 2016 post. "A candidate for President cannot make America prosperous if he doesn't understand that America's cities are, in fact, the backbone of the national economy."

Prior to de Blasio's announcement, other mayors from across the country spoke. Watch:

CNN and the Associated Press contributed to this report.