New York City Mayor Bill de Blasio gave Mayor Rahm Emanuel a ringing endorsement in a Friday speech at the City Club of Chicago.

De Blasio, who is up for re-election this year and fundraising in Chicago, was asked by audience members what advice he’d give Emanuel regarding the city’s struggle with gun violence.

“The challenges Chicago faces, in my view, Rahm Emanuel’s the only person with the strength to address these issues,” de Blasio said.

The two Democratic mayors met earlier Friday, but de Blasio didn’t specify what they talked about.

At the luncheon, de Blasio defended Emanuel, but stopped short of giving him advice on how to handle Chicago’s violence problem, despite the fact that New York City has been experiencing historically low crime statistics. According to the NYPD, last year the city had less than 1,000 shootings for the first time since the mid 1990s. Meanwhile in Chicago, 2016 saw the highest homicide total in nearly 20 years, with many killings going unsolved.

De Blasio said every city has to figure out its own path to solving these problems, and New York City has been making major changes over the last 25 years.

And he said he believes President Donald Trump’s repeated tweets about Chicago’s violence weren’t helping.

“I’ll be very blunt,” de Blasio said. “I am sick of President Trump denigrating Chicago. And again, it’s become his surrogate for what he thinks about all cities. And I don’t get it, because he’s a born and bred New Yorker, it’s not like he hasn’t lived in an urban area.”

De Blasio called Trump’s tweets “painful stereotyping of cities,” and suggested the federal government should instead provide support to Chicago to hire more police officers.

“Stray tweets in the middle of the night are not stopping crime,” he said.

Prior to the discussion, Maggiano’s, the longtime host of the City Club’s luncheons, supplemented its usual Italian lunch menu with boxes of Lou Malnati’s deep-dish pizza. The selection was immediately labeled on Twitter as a supreme act of “trolling.” In 2014, Mayor de Blasio was spotted eating New York pizza with utensils, instead of his hands. An internet firestorm ensued.

Special menu for Mayor @BilldeBlasio‘s speech at the City Club luncheon: @LouMalnatis pizza 🍕 pic.twitter.com/wWf0Ln6oAj — Lauren Chooljian (@laurenchooljian) March 3, 2017

As often happens when New Yorkers visit the so-called “second city,” de Blasio’s Chicago speech eventually devolved into a debate about which city is better. De Blasio mentioned he ate at Portillo’s for lunch, but said “the jury is still out” on which city has the better hot dog.

“Nathan’s can give them quite a run for their money,” he said.

Naturally, the Chicago audience groaned.

Lauren Chooljian covers city politics for WBEZ. Follow her @laurenchooljian.