Story highlights DHS Secretary believes North Korea president "knows what he's doing"

Kelly adds his name to list of US officials who think Kim Jong Un is rational

Washington (CNN) Shortly after news broke of another North Korean missile test, Department of Homeland Security Secretary John Kelly said the country's dictator, Kim Jong Un, "seems like someone who knows what he's doing."

Asked by CNN's Jake Tapper on "The Lead" whether the North Korean president is "mentally unbalanced," Kelly responded that "clearly the No. 1 thing in his mind is to remain in power."

Kim appears to be solidifying his power by instilling fear in his subjects and showcasing military might, Kelly said.

The DHS secretary admitted he may not be the best person to assess Kim's mental state, telling Tapper: "The only way to decide whether he's insane or not is to lay him down on a couch and have a battalion's worth of therapists figure him out."

Secretary of State Rex Tillerson said Thursda y that he also believes Kim is a rational actor.

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