CNN White House reporter Jim Acosta visited comedian Jimmy Kimmel's ABC talk show and discussed his coverage of the Obama and Trump administrations.

Kimmel said Acosta has an ongoing tenuous relationship with the White House, to the point where then-President-elect Donald Trump singled him out in a press conference to tell him he was "fake news."

Acosta, 47, told Kimmel that when he covered the Obama White House, he was "just as tough on him" as he is on Trump.

He said he once asked Obama why he hadn't crushed ISIS "bastards," and the administration did not take kindly to it.

'You Are Fake News!': Trump Refuses to Let CNN Reporter Ask Question

'Out': Trump Tells CNN's Acosta to Leave After Questions About 'S***hole' Controversy

But, he said Trump and his press shop likely consider him their least favorite reporter.

"I'm hated by the worst people," he said, adding that he's the only reporter ever to be kicked out of a president's press availability. Acosta said he considered it "a badge of honor."

Acosta said that despite their often fiery exchanges, he has a good working relationship with Press Secretary Sarah Sanders.

Kimmel characterized Acosta's on-camera relationship with the White House as a "thorn in the flabby underbelly of the Trump administration."

Sean Hannity questioned Acosta's characterization of his past coverage, playing a clip from June 2015 in which he asked Obama about his "best week ever."

"All he needed was a set of pom-poms. ... Why doesn't he just admit he's a liberal activist who hates Donald Trump?" said Hannity.

Spicer: 'Really Sad' to See CNN's Acosta 'Making Fun' of Trump Voters

'Let Me List a Few': Sanders, Acosta Spar Over Trump's Actions Against Russia

Spicer Blasts 'Carnival Barker' Jim Acosta Over Twitter Spat With Sanders