Flake said on CNN's "State of the Union" Sunday that Trump is sending the wrong message by discussing backing out of a trade deal between the U.S. and South Korea while North Korea has developed a hydrogen bomb, which they tested Saturday.
"No, not at all. I don't think that that would be good in any circumstances," Flake said when asked if he thinks it's a positive move to pull out of the deal. "Now it's particularly troubling, given what South Korea is faced with. I think that we need to do more trade, not less, and withdrawing from trade agreements is a very troubling sign."
The Washington Post reported Saturday Trump is preparing to pull out of the U.S.- Korea Free Trade Agreement.
Critics of the president believe the administration should not be pulling out of any sort of deal supporting South Korea at a time when tensions with the North are escalating.
Flake said Trump must rely on his national security team to deal with a thermonuclear North Korea to make up for his lack of experience in foreign relations.
Flake added no president has the required experience to deal with nuclear weapons negotiations when they enter office. Flake, who has been a frequent critic of Trump, notably refused to critique Trump's statements Sunday morning about North Korea's latest nuclear test, in which Trump slammed both China and South Korea.
"No president comes in prepared with regard to foreign policy experience. That's why you have a good team around them. I've had my concerns, I think everyone has, as some of the statements made by the president with regard to NATO and other areas in foreign policy. Like I said, I think we want somebody who is measured and sober and consistent and conservative in this regard, but he has a good team around him and I have confidence in them."