CHICAGO (CBS) — President Donald Trump again decried gun violence in Chicago, this time blaming the crime in part on undocumented immigrants.

“You look at Chicago, and you look at other places,” the president said Wednesday. “So many of the problems are caused by gang members, many of whom are not even legally in our country.”

Trump, speaking to a gathering of police chiefs and sheriffs in Washington, D.C. called for “national action” in Chicago.

“I don’t know anyone in Chicago who believes that,” said Cook County Board President, Toni Preckwinkle. “Whether we are talking about African American or Latino neighborhoods, we are not talking about illegal immigrants. We are talking about our native born sons and daughters.”

President Trump previously has said he would “call in the feds” if Mayor Emanuel and his police department could not reduce crime. Trump hasn’t provided details on what form the federal help would take, but the mayor has said he would welcome more federal agents and prosecutors to help stop gun violence.

“What is going on in Chicago?” Trump said. “We cannot allow this to continue,” saying too many lives are “claimed by gangs.”

It is the fist time Trump has linked immigration to Chicago’s gang problem, but he did not specify where the immigrants came from. His administration is fighting a legal battle to enforce a temporary travel ban on citizens from seven Muslim-majority countries and he has made plans to build a wall along the U.S.-Mexico border a centerpiece of his presidency.

“With all the talk and no action, you have to wonder whether the administration is serious about working with us on solutions, or if they are just using violence in this great city to score political points. We’ve been clear. There are ways the federal government can help, and we’re happy to partner with the administration whenever they decide to stop talking and start acting,” Emanuel spokesman Matt McGrath said.

In 2016, there were 762 homicides in Chicago, more than New York and Los Angeles combined.

The bulk of the deaths and shooting incidents, which jumped from 2,426 in 2015 to 3,550 last year, occurred in five neighborhoods on the city’s South and West sides, all poor and predominantly black areas where gangs are most active.

Officials in Chicago haven’t linked the violence to an influx of illegal immigrants. Rather, they say, prison sentences for gun crimes are too lenient, allowing repeat offenders with gang ties out on the street to commit more violence.

Statistics from those five neighborhoods also show that 80 percent of the victims have been identified by police as having gang affiliations.

The city has scrambled to address the violence. Emanuel announced last year that 1,000 officers would be added to the police department.

Trump on Wednesday also repeated his promise to build the Mexico border wall.

“I don’t kid,” he said, adding the wall was being “designed right now.”