Speaking at Duke University, Kelly most notably diverged from his former boss on matters of immigration.

Kelly made clear that he does not agree with the administration’s decision to declare a national emergency to obtain funding for the border wall, saying “we don’t need a wall from sea to shining sea.” While Kelly said there are areas where a border wall would in fact be effective, he called a border wall spanning the entire U.S.-Mexico border a “waste of money.”

Kelly also appeared to disagree with Trump’s characterization of individuals crossing the southern border into the U.S. as lawless, dangerous criminals. “They’re overwhelmingly not criminals,” he said. “They’re people coming up here for economic purposes. I don’t blame them for that.”

Kelly also expressed opposition to both the family separation policy enacted by the administration and Trump’s decision to deploy National Guard troops to the border. Kelly noted that the zero-tolerance policy that resulted in family separations “kind of surprised” him and some of his colleagues, claiming that it was a decision made by then-Attorney General Jeff Sessions. “It certainly caught DHS flat-footed and HHS, Health and Human Services, flat-footed,” he said. On the deployment of troops to the border, Kelly suggested that he “would always look for another way to do it.”

Kelly, a retired four-star general, served nearly two years in the Trump administration, first as Homeland Security secretary, and then as Trump’s chief of staff.