Trump’s former chief of staff John Kelly blamed the fallout from the controversial “zero-tolerance” policy of separating migrant children from their parents on then-U.S. Attorney General Jeff Sessions.

“The big separation of families, that was a decision made by the Attorney General” Kelly said in comments Wednesday to a crowd of several hundred at Duke University in Durham, N.C. in one of his first public addresses since leaving the White House.

“It kind of surprised us,” Kelly added. “It certainly caught DHS”—the Department of Homeland Security Kelly—“flat-footed and HHS, Health and Human Services, flat-footed.”

Kelly did not mention that when he ran DHS, he said family separation was under consideration.

In the talk at Duke, Kelly spoke candidly at times about his time in the White House, calling it the “least enjoyable job” of his life and joking that his best advice for successor Mick Mulvaney was to “run for it.”

His comments about the border situation run counter to how his former boss has portrayed the situation. Kelly talking about he garnered insight leading the U.S. Southern Command as a Marine general into how American demand for illicit drugs destabilized countries south of the border and pushed many to flee from violence.

And that crime in those nations “is almost entirely based on our drug consumption” and the power drug cartels received from the push north for drugs, he said.

Kelly went on to say that he views the migration north as a response to economic conditions.

“They’re overwhelmingly not criminals,” he said. “They’re people coming up here for economic purposes.”

In his talk, Kelly talked candidly at time about his frustrations with the press, saying it was more focused on interpersonal dynamics inside the White House instead of substantive issues.

“The press does the best they can to get the stories they can publish to become popular or famous,” he said. “They’re not always accurate.”

He declined to answer a question from moderator Peter Fever, a Duke University professor, about whether Kelly had authored memorandums to create a written record of events.

“I’d prefer not to talk about that,” he said.

He also didn't bite when asked to respond to recent reports that Trump unsuccessfully tried to pressure Kelly and White House counsel Don McGahn to green-light security clearances for daughter Ivanka Trump and her husband Jared Kushner over their own recommendations.

Kelly cited the need to keep details about security clearances confidential and conversations with the president confidential even as he insinuated that press reports about the decision had not necessarily been accurate.