President Donald Trump's "fire and fury" warning to North Korea over its nuclear capabilities "initially was over the top," but it was effectively "tamped down" by Secretary of State Rex Tillerson on Wednesday, according to former U.S. Ambassador to the United Nations Bill Richardson.
"The president has his own style," Richardson, also a former New Mexico governor, told Fox News' "America's Newsroom" anchor Bill Hemmer. "This is how he acts and responds. I don't think he is going to change. But this is a grave threat, and this is not a time when we should be partisan."
Trump has the chance to bring the United States together with a strategy in dealing with North Korea, Richardson added, that "involves sanctions, military exercises continuing, and then ultimately diplomacy."
Tillerson, meanwhile, has the right approach, in calling on North Korea to stop its nuclear and intercontinental ballistics missile testing in exchange for a dialogue and possibly a short-term deal, Richardson said.
Hemmer said Trump is communicating directly with North Korean leader Kim Jong Un in "language that only he understands," but Richardson said there is a danger in that.
"I've known the North Koreans," Richardson said. "I've negotiated with them in the past. You don't know how they are going to react, but at the same time they engage in this fiery rhetoric almost every day."
Such threats, he continued, are part of North Korea's "foreign policy bombastic theories that they'll scare everybody."
However, Richardson said he does not want Trump to engage in a "tit-for-tat" every day about North Korea's threats.
"That's why I was concerned about his comments," said Richardson about Trump, while Tillerson delivered a more calming message.
"I think that is important," Richardson said. "This is a grave threat. But we've got to approach it in a way that the country comes together. This is the gravest threat facing us now, as you pointed out, with those missiles. We have to get our intelligence community to be more effective in telling us about some of these problems."
But putting aside Trump's comments, Richardson said to look U.S. policy toward North Korea, and the former diplomat said Tillerson and the State Department should manage that policy.
"Let's not have mixed messages from the National Security Advisor, the U.N. Ambassador, the Secretary of Defense," Richardson said. "Let's pursue a policy of diplomacy banked by sanctions and military cooperation in the region and let's see if China does help us for a change."
Richardson said he does believe a set of strong sanctions approved by the U.N. Security Council against North Korea were a "very important step."
"These sanctions have bite," he told Hemmer. "They affect coal exports, seafood, North Korean workers working on oil. Eighty percent of the commerce going into North Korea comes through China. The problem is China has not enforced them and a lot of cross border smuggling goes in."
Russia can also play a role in the North Korean matter, Richardson said.
"Maybe we've turned a little corner," he said. "Let's be careful. You never know how the North Koreans are going to act. They don't think like us and they don't react like us. It's a cult of personality controlled by Kim Jong-un. He is a total mystery. We don't know what he will do next."