Arizona Republican Sen. Jeff Flake told Dana Bash on CNN's "State of the Union" Sunday that Trump, like most new presidents, was inexperienced in foreign policy, adding that he would like a "measured" response from the Oval Office.
"Obviously, you'd like a leader that is measured and sober and consistent," Flake said, adding, "We've got a good team around the President."
Flake echoed the administration's previous statements on the North Korean nuclear threat, saying all options needed to be on the table -- including military ones -- and said there is no clear path forward to resolving Pyongyang's continued nuclear development.
"It becomes cliche to say there are no good options here, but there really aren't," Flake said.
Flake said China has "considerably more leverage" than the US over North Korea, and he hoped Beijing would use that leverage to help alleviate the crisis, but he also acknowledged international sanctions on Pyongyang had not slowed the rogue state's nuclear program.
"They seem intent on moving forward," Flake said.
A top Trump target
Flake criticized Trump during the campaign, and since he took office, the senator has said he is willing to part with Trump on key items of the President's agenda.
Flake has supported Trump's nominees and voted with him on a number of issues that have come before the Senate, including GOP proposals to repeal and replace Obamacare. But the Arizona senator has also staked out positions opposing Trump on immigration and the proposed border wall.
Trump promised during the campaign to end the Deferred Action for Childhood Arrivals program, which protects undocumented immigrants who came to the US as children from deportation. Flake said Sunday that "it would be the right thing" for Trump to go back on that promise.
"To remove them from the country, to split up families like this, is just not the way we ought to go," Flake said.
On Trump's proposed border wall, Flake said it was still unclear to him what Trump was actually proposing.
"We still really haven't seen what he means by the wall," Flake said. "If that's a metaphor for border security, we can certainly support that. But if he's talking about a solitary, brick-and-mortar, 2,000-mile edifice on the border, then no, nobody ought to support that."
Flake's criticisms of Trump have earned the ire of the President, who most recently criticized him -- but not by name -- during a rally in Flake's state of Arizona. But in the interview Sunday, Flake said he was not worried about Trump hurting his reelection chances.
"The people in Arizona tend to elect independent-minded, principled senators," Flake said.
He added, "I'm quite comfortable being where I am."