Days earlier, a federal judge in Chicago at least temporarily blocked the administration's attempt to withhold public safety grant money from cities that don't cooperate Sessions said in a speech in Portland, Oregon that the grants are not an entitlement.
He also says they cannot be given to cities that actively frustrate efforts to reduce crime.
Sessions highlighted the case of Sergio Martinez, who was accused of assaulting two women in July after his release from a Portland jail. Martinez had been deported from the U.S. more than a dozen times.
Demonstrators protested Sessions' appearance in Portland.
The Trump administration is appealing a judge's ruling that blocks its effort to withhold funding from "sanctuary cities" that limit cooperation with U.S. immigration authorities.
The administration filed the appeal with the 9th U.S. Circuit Court of Appeals on Monday.
U.S. District Judge William Orrick has temporarily halted President Donald Trump's order in two lawsuits. One was brought by the city of San Francisco and the one by California's Santa Clara County.
The judge rejected the administration's argument that the executive order applies only to a relatively small pot of money and said Trump cannot set new conditions on spending approved by Congress.
The administration has since moved to withhold one particular law enforcement grant from sanctuary cities, prompting a new round of lawsuits. A federal judge in Illinois blocked that move Friday.