The threat of withholding grants from so-called sanctuary cities that protect immigrants doesn't appear to be swaying Chicago Mayor Rahm Emanuel.
However, Emanuel told CNBC's "Closing Bell" on Monday that Chicago will still be a "welcoming city" for immigrants.
"In the city of Chicago, like New York, like Boston, like Philadelphia, like San Francisco, like Seattle, we welcome people to our cities from other shores who want to innovate, want to be entrepreneurs, who want to bring their families and give their children the chance at the American dream," said Emanuel, who noted his grandfather came to this country as an immigrant in 1917.
"I believe that people who have that dream and sacrifice and struggle to give their kids a chance at that American dream, we're going to honor."
Sanctuary cities help illegal immigrants avoid deportation by limiting cooperation with federal immigration authorities and other agencies.
Sessions argued the failure to deport aliens who are convicted of criminal offenses puts communities at risk.
"I strongly urge our nation's states and cities and counties to consider carefully the harm they are doing to their citizens by refusing to enforce our immigration laws and to rethink these policies," Sessions said.
—Reuters contributed to this report.