Sen. Bob Corker, the chairman of the Senate Foreign Relations Committee who has very publicly parted with the president lately, said a "binary choice" is developingif diplomacy fails, and worries the White House has "kneecapped" Secretary of Stat e Rex Tillerson.
"And that binary choice is we are either going to allow him to have a nuclear weapon that's deliverable to the United States," said Corker, speaking at the Tennessee Department of Economic Community Development's Governors Conference in Nashville, Tennessee, on Friday. "The president says that's never going to happen. Or we're going to go in and get involved militarily."
That latter option, he said, would be deadly.
"We're talking about millions of people being dead, quickly," Corker said, snapping his fingers, "if we get involved in kinetic activity and likely it leads to a regional or global war because you're bringing in South Korea, Japan, China, probably Russia. So again the only solution right now that is going to work for us and work for the region is Tillerson continuing to do the things that he's doing right now with China. He's got a backchannel into North Korea. Short of that we're going to end up in a binary choice…" Corker said.
As the White House grapples with North Korea's developing nuclear program, Corker expressed relief that Secretary of State Rex Tillerson thinks "a little different from the White House." But he also worries the White House has "kneecapped" him, particularly on any efforts to work with China in regards to North Korea.
"Rex Tillerson, our secretary of state, is someone I spend a lot of time with," Corker said. "I support him probably more than anyone in Washington because I know the importance of his role and because I know he's a good strategic thinker. And he sometimes thinks a little different from the White House, thankfully."
"But he has been kneecapped on several occasions when he's at a place with North Korea, I mean with China, and we get off track," he said.
Corker, who is not running for re-election in 2018, has become one of the president's most vocal critics, calling the White House an "adult day care" and questioning the president's ability to lead. Mr. Trump has returned the fire, calling him.
CBS News' Alan He contributed to this report.