Sen. Bernie Sanders (I-VT) ended a Thursday interview with an Arizona TV station KPNX right after a reporter questioned him about his wife’s unplanned meeting with notorious Sheriff Joe Arpaio.

“What Joe Arpaio is doing is an outrage,” Sanders told KPNX reporter Brahm Resnick.

“My wife went to look at the so-called Tent City, which is something that should not exist,” he continued, referring to the outdoor jail run by the openly anti-immigrant sheriff of Maricopa County. “The fact that he crashed her meeting is, to me, very, very wrong, not something he should have done.”

Sanders briefly discussed his proposals to improve conditions for immigrants in the U.S. before abruptly ending the interview with a “thank you very much.” The visibly frustrated Vermont senator took off his mic and stood up, as Resnick can be heard asking him if he would consider being Hillary Clinton’s vice president.

“Thank you very much,” Sanders says again, handing him the mic.

“The first candidate who has ever walked away,” Resnick then said, sounding surprised.

“I didn’t walk away,” Sanders shot back. “I told you you had four minutes, you had more than four minutes. I didn’t walk away. You persisted.”

“I’m a reporter. That’s what we do,” Resnick replied.

After a beat, Sanders prodded Resnick again: “Don’t say I walked away. You got four minutes.”

“We’re not going to squabble over this,” Resnick responded.

KNPX’s footage shows that the full interview ran exactly four minutes.

Jane Sanders visited Tent City on Wednesday to assess conditions at the outdoor jail, where temperatures routinely reach into the triple digits. Arpaio approached her after holding his own press conference, and they engaged in a tense back-and-forth over the treatment of Tent City inmates and allegations that Arpaio racially profiles Latino immigrants.

Sanders described the “un-American” Arpaio’s encounter with his wife as an “ambush” at a Thursday rally.

Watch the tail end of Sanders’ interview with Resnick below:

h/t The Hill