WASHINGTON : Republican presidential front-runner Donald Trump says North Korean leader Kim Jong-un deserves “credit” for the efficiency with which he disposes of his political foes.

“You’ve got to give him credit: How many young guys - he was like 26 or 25 when his father died - take over these tough generals and all of a sudden, you know, it’s pretty amazing when you think of it. How does he do that?,” Trump said at a rally in Ottumwa, Iowa, on Saturday. “Even though it is a culture, and it’s a culture thing, he goes in, he takes over, he’s the boss. It’s incredible.” After North Korea’s government said it successfully tested a hydrogen bomb earlier this week, Trump called Kim a “madman playing around with nukes” and a “total nut job.” But he also said that Kim had some admirable qualities. “I mean, it’s amazing that a young guy would go over and take over,” Trump said Thursday on Fox News’ “On the Record.”

“You know, you would have thought that these tough generals would have said no way this is gonna happen when the father died. “So he’s gotta have something going for him, because he kept control, which is amazing for a young person to do,” he added.

It was the latest in a series of controversial comments by the Republican front-runner, whose campaign has attracted attention from such statements since the beginning.

Kim ordered the execution of several top officials last year, including two vice ministers, according to South Korean intelligence. He also purged and executed his once-powerful uncle for treachery in 2013.

Trump has previously praised other world leaders about whom Americans hold negative views. He called Russian President Vladimir Putin a “highly respected” man in global affairs, after the Russian strongman called Trump “bright and talented.”