Top US politician John Boehner has compared Republican presidential candidate Ted Cruz to the devil.

Boehner, a Republican who served as speaker of the House of Representatives from 2011 to 2015, described Cruz as "Lucifer in the flesh" in an interview at Stanford University.

Asked about Cruz, Boehner told history professor David Kennedy: "Lucifer in the flesh." He went on: "I have Democrat friends and Republican friends. I get along with almost everyone, but I have never worked with a more miserable son of a b*** in my life," according to the Stanford Daily.

He has previously called on Paul Ryan, who succeeded him as speaker, to go for the Republican nomination.

Boehner, who has described himself as "texting buddies" with front-runner Donald Trump, opened his talk by saying: "You can call me boner, beaner, jackass, happy to answer to almost anything."

He has repeatedly clashed with Cruz. 

He compared him to the devil in another talk in Florida last month.

The two have often disagreed over Obamacare.

Cruz tweeted a response:

Cruz also told reporters: "The interesting thing is I've never worked with John Boehner, I don't know the man. Indeed, during the government shut down, I reached out to John Boehner, to work with him to get something meaningful done. He said, 'I have no interest in talking to you.' "

Cruz continued: "When John Boehner calls me Lucifer, he is directing it at you. What Boehner is angry at is me standing with the American people."