Donald Trump berated the head of Chicago’s police force on Monday, faulting him for the city’s murder rate and critical remarks he’s made about the president.

“He’s not doing his job,” Trump said of Eddie Johnson, superintendent of the Chicago Police Department, at a gathering of the International Association of Chiefs of Police in Chicago. “It’s embarrassing to us as a nation. All over the world they’re talking about Chicago. Afghanistan is a safe place by comparison, it’s true.”

Johnson opted not to attend the event with Trump, saying, “The values of the people of Chicago are more important than anything he would have to say.”

Trump called the comments “insulting.”

“There is one person that’s not here today,” Trump said. “I said, ‘Where is he, I want to talk to him.’ In fact, more than anyone else, this person should be here, because maybe he could learn something.”

Trump said Chicago had about 565 murders last year, a figure roughly in line with a tally by the Chicago Tribune.

As part of the event, Trump planned to sign an executive order creating a commission to study the causes of crime—a move he has said is aimed at reducing the number of mass shootings.

Trump on Monday also attended a fundraiser at Trump Tower hosted by Cubs co-owner Todd Ricketts, where 250 people were expected, according to reports: