About 20 additional agents from the U.S. Bureau of Alcohol, Tobacco, Firearms and Explosives are headed to Chicago, less than two weeks after President Donald Trump threatened to “send in the Feds,” sources told the Chicago Sun-Times.

David Coulson, a spokesman for the Chicago field office of the ATF, said: “We are always seeking to enhance the enforcement efforts of ATF … in conjunction with CPD.”

The decision to send the agents to Chicago was first reported by CNN.

Sources said about 20 agents will join the Chicago field office, which has a total staff of about 120 and covers the city, the suburbs and northwest Indiana.

Citing two law enforcement officials, CNN reported the move is an effort to “beef up” the federal presence in the city, up from about 40 agents now based in Chicago.

Adam Collins, a spokesman for Mayor Rahm Emanuel, said in an emailed statement Friday evening the mayor’s office was not aware of any new federal agents coming to the city, though they would be welcome.

“We have received no word from the federal government to confirm these reports, but it would be welcome news if the administration has indeed agreed to one of Mayor Emanuel’s requests for federal resources,” Collins said. “We remain hopeful that they will also provide added DEA and FBI agents, that they will boost the prosecution rate for federal gun crimes in Chicago and that they will provide funding for successful violence prevention efforts.”

Reports of the ATF sending more agents came as a surprise to some in City Hall.

“We first heard about this on CNN,” a City Hall source said.

A spokesman for the Chicago Police Department also could not provide details about the agents.

Sources within the ATF in Chicago welcome a move to hire additional permanent agents here, but they warn that must come with more aggressive prosecution of gun cases on the federal and state levels.

Last year, the Chicago Sun-Times reported that federal gun prosecutions in Chicago lagged other cities including Baltimore, Detroit, Milwaukee, Brooklyn and Manhattan between 2011 and 2016.

ATF sources said a boost in permanent staffing of agents here would be far more preferable than the four-month surge of ATF agents who were brought to Chicago in 2014 under then-Attorney General Eric Holder. Under that initiative, 90 state and federal defendants were arrested, authorities said.

In addition, Holder assigned seven more full-time ATF agents to the city at that time to assist the 45 already assigned to Chicago. Another 20 to 30 were temporarily sent to the city.

A survey of police chiefs across the country recently found such a temporary surge of federal agents ranks low on the list of ways they think the federal government can help their departments.

The news of more ATF agents in the city comes 10 days after Trump yet again dragged Chicago’s rampant gun violence into the national spotlight.

“If Chicago doesn’t fix the horrible “carnage” going on, 228 shootings in 2017 with 42 killings (up 24% from 2016), I will send in the Feds!” Trump tweeted on Jan. 24.

It was unclear what Trump meant by “send in the Feds!” though CNN reported that a bulletin was sent out to ATF field offices around the country asking for volunteers to come to Chicago.

Emanuel discussed federal assistance with Trump when he met with the then president-elect at Trump Tower in Manhattan on Dec. 7. Emanuel said he made a pitch for federal assistance to boost police hiring and youth mentoring programs that he hoped will stop a 50 percent surge in homicides and shootings.

Chicago Police Supt. Eddie Johnson previously told the Sun-Times, “the Chicago Police Department is more than willing to work with the federal government to build on our partnerships with DOJ, FBI, DEA and ATF and boost federal prosecution rates for gun crimes in Chicago.”

Last month, Trump, while still president-elect, addressed via Twitter Chicago’s crime surge, saying Emanuel should ask for “federal help.”  “Chicago murder rate is record setting — 4,331 shooting victims with 762 murders in 2016. If Mayor can’t do it he must ask for Federal help!” Trump said in a tweet.

However, Emanuel had already asked Trump for assistance — when they met in New York the previous month.