U.S. President-elect Donald Trump said Monday that the mayor of crime-ridden Chicago, former White House chief of staff Rahm Emanuel, ought to seek federal law enforcement help if he can’t control the soaring murder rate in the country’s third biggest city.

Trump, in a Twitter comment, said, “Chicago murder rate is record-setting — 4,331 shooting victims with 762 murders in 2016,” more than two slayings a day.

“If Mayor can’t do it he must ask for federal help!” Trump said.

The Chicago murder toll, often the result of gang turf wars and drug disputes in impoverished neighborhoods, was the city’s highest in 20 years and eclipsed the combined total of New York and Los Angeles, the two biggest American cities.

Emanuel, a Trump political opponent, served early on as President Barack Obama’s White House chief of staff. Emanuel left Washington in 2010 to run the first of his two successful campaigns to be mayor of Chicago, with its 2.7 million residents.

Despite his past attacks on Trump, Emanuel, like other big-city mayors, has met with the president-elect ahead of his January 20 inauguration. During their December meeting, Emanuel urged Trump to reconsider his hard-line stance against illegal immigration, one of the hallmarks of the real estate mogul’s upset win for the presidency.