John McCain described ruling out possible military action as "foolish." | AP Photo McCain on pre-emptive strike on North Korea: 'We have to consider that option'

Sen. John McCain said Sunday the Trump administration should consider a pre-emptive strike against North Korea if the U.S. determines that country's regime can mount a nuclear weapon onto a ballistic missile, but cautioned military action should be last resort.

"I think that we have to consider that option as the very last option, and for a number of reasons," McCain said on CNN's "State of the Union." The Arizona Republican described ruling out possible military action as "foolish."


McCain, who chairs the Senate Armed Services Committee, said one of the reasons for caution is the close proximity of the populous South Korean capital, Seoul, to North Korea. Should a shooting war break out, McCain said, "The carnage would be horrendous."

McCain told host Jake Tapper he didn't think Trump was considering a pre-emptive strike against the North Korean regime. McCain called on China to use its leverage over North Korea to "put the brakes on this."

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"This is very serious. Their capabilities of firing artillery on Seoul is absolutely real," McCain said. "And this, again, is why we have to bring every pressure to bear. And the major lever on North Korea today, and maybe the only lever, is China."

"But to say you absolutely rule out that option, of course, would be foolish," the Arizona Republican added. "But it has to be the ultimate last option."