US President Donald Trump has used a conference of police chiefs to describe host city Chicago as "embarrassing" under the leadership of its top officer.
Mr Trump has frequently criticised Chicago for its crime problems and status as a sanctuary city, one of scores of cities around the country that refuse to work with federal authorities to round up people who are living in the US illegally.
Mr Trump said: "It's embarrassing to us as a nation. All over the world they're talking about Chicago. Afghanistan is a safe place by comparison."
He also lashed out at Police Superintendent Eddie Johnson, who angered Chicago's police by skipping Trump's first appearance in the city as president.
"More than anyone else he should be here, because maybe he could maybe learn something," Mr Trump said, claiming Mr Johnson puts the needs of illegal immigrants above the needs of the law-abiding residents of Chicago.
"Those are his values and frankly those values to me are a disgrace," Trump said, vowing to never give priority to the needs of illegal immigrants. "I want Eddie Johnson to change his values and to change them fast."
Mr Johnson's decision to skip Mr Trump's address angered the city's chapter of the Fraternal Order of Police, which said in a Facebook post that "such a gesture would be an insult to both President Trump and the office of the presidency itself and would be a mark of disgrace upon the city throughout the entire nation, including Mayor Lori Lightfoot".
Protesters gather across the Chicago River from the Trump International Hotel and Tower while President Trump attends a fundraiser. Source: AAP
Ms Lightfoot has also refused to meet with Trump while he is in her city.
Then FOP Lodge 7, which represents rank-and-file Chicago police officers, announced that it had cast a vote of no confidence in Johnson.
The vote might please Trump, who likes to tell officers not to treat crime suspects so gently and was cheered at last year's gathering of the same police chiefs' organisation in Orlando, Florida, when he advocated the use of the "stop and frisk" policing tactic that has been deemed unconstitutional.
At the conference, Mr Trump signed an executive order creating a presidential commission on law enforcement to study issues like substance abuse, homelessness and mental illness, the White House said.
The order calls for establishing a framework for better training, recruiting and retaining law enforcement officers.
The president also announced that the Justice Department will begin a stronger crackdown on violent crime in the US, targeting gang members and drug traffickers in high-crime areas.
"Let's call it the surge," Mr Trump said.
While in Chicago, Trump is scheduled to headline a campaign luncheon that is set to raise approximately $US4 million for a joint fundraising committee benefiting Mr Trump's re-election effort and the Republican National Committee, according to the Republicans.
