"It's pretty much business as usual, but we have to stop and ponder the words and think about what would happen if a crazy man actually takes it to an extreme," he said.
Huntsman, who also ran for the Republican nomination for president in 2012, said that while Kim Jong Un's threats are not unusual for the historically bellicose nation, "you don't know what he's capable of."
And he expressed concern that "Dennis Rodman, the American basketball player, has probably spent more face-time with Kim Jong Un than the president of China."
Rodman visited the nation earlier this year, and met with the nation's leader, whom he calls his "friend."
Huntsman did say that one good thing could come out of North Korea's recent provocations: An opportunity to engage with China in pursuit of a common goal.
"This is a huge opening, believe me, with China, because our interests, for the first time in a long while, are aligned. We both want to get something done and bring the level of tension down on the Korean peninsula," he said.