McCain: Kim Jong Un is 'a clown'

“There’s a city of Seoul with millions of people," McCain said. "This is very dangerous business. Now logically, would he ever contemplate such a thing? I think it’s pretty clear this guy and his father and grandfather didn’t think like us.”

McCain said that he believed the Pentagon should attempt to shoot down any test missile fired by Pyongyang as a show of American military strength.

“I would take it out,” McCain said. “We show young Kim Jong Un that we can take out his capabilities. We can show that to him.”

On Friday, Secretary of State John Kerry blasted North Korean posturing as "simply unacceptable" during a press conference in Seoul.

"I am here to make it clear today on behalf of President Obama and the citizens of the United States and our bilateral security agreement, that the United States will defend its allies and itself," he said.