The chair of the Senate foreign relations committee has predicted Donald Trump will pull the US out of the nuclear deal with Iran.

“The Iran deal will be another issue that’s coming up in May, and right now it doesn’t feel like it’s going to be extended,” Bob Corker told CBS’s Face the Nation in an interview broadcast on Sunday.

“I think the president likely will move away from it, unless our European counterparts really come together on a framework. And it doesn’t feel to me that they are. Now, as we get within two weeks of the 12 May date, that could change.”

Corker also said he did not think such a move would damage attempts to set up a meeting the same month between Trump and Kim Jong-un, the dictator of nuclear-armed North Korea.

The Tennessee senator has clashed repeatedly with Trump and will retire in November. He has been touted in some quarters as a presidential rival in 2020.

In his CBS interview, he said: “This whole situation with North Korea … is somewhat unorthodox, and I think you’re dealing with a leader there that probably doesn’t think the same way that other countries and their leadership might. So I’m not sure that [ending the Iran deal] is gonna end up having a detrimental effect.”

Trump has long opposed the 2015 deal, which curtails Tehran’s development of nuclear weapons in return for sanctions relief, partly because his predecessor in the White House, Barack Obama, regarded it as a signature achievement.

This week Trump fired the secretary of state, Rex Tillerson, a defender of the deal, and nominated the CIA director, Mike Pompeo, to replace him.

“I wanted to either break it or do something and he felt a little bit differently,” Trump told reporters. “So we were not really thinking the same. With Mike, Mike Pompeo, we have a very similar thought process.”

Trump is also reported to be close to replacing the national security adviser, HR McMaster, another defender of the deal, with the former Bush UN ambassador John Bolton, a hawk who favours pre-emptive military action.

Corker said he thought Pompeo had a good chance of being confirmed by his committee, even though Rand Paul of Kentucky has said he will vote no.

Senator Rand Paul said Mike Pompeo, the proposed new secretary of state, was ‘too much of an advocate for regime change, really everywhere’. Photograph: Win McNamee/Getty Images

Paul spoke to CNN’s State of the Union. “I don’t think you really want people who are eager for war to be running the state department,” he said. “You want a diplomat.”

Pompeo, he said, was “too much of an advocate for regime change, really everywhere” and was not a “good fit to be a diplomat”.

Paul is also opposed to the appointment of Gina Haspel as Pompeo’s successor at the CIA. He told CBS there was “no evidence [Haspel] was protesting against torture” when she oversaw “enhanced interrogation” under the Bush administration.

“There’s every evidence she was covering it up,” he said.

Tillerson, Corker said, was “doing fine” despite reportedly having been fired in an undignified manner: the White House chief of staff, John Kelly, claimed Tillerson took a warning call from him while on the toilet, and Tillerson then learned of the final decision by tweet.

Corker added that he thought Trump “likes to hear diverse opinions”.

“But once a decision is made,” he said, “I think [Trump] likes to see it move along quickly. And I think that was one of the frustrations he may have had with Secretary Tillerson.”