Donald Trump and his running mate, Indiana Gov. Mike Pence, briefly discussed the topic of negative campaigning in an excerpt of their first joint interview released Saturday.

The full “60 Minutes” interview will air Sunday night at 7 p.m. ET. In the excerpt, CBS News’ Lesley Stahl asked about a essay Pence wrote in which he said that negative campaigning was wrong.

“I think this is a good man who’s been talking about the issues the American people care about,” Pence said.

Stahl asked about the nicknames Trump used on the campaign trail, including “Lyin’ Ted” — his nickname for Sen. Ted Cruz (R-TX).

Pence said that he wrote the essay “a long time ago.”

“I said campaigns oughta be about something more important than just one candidate’s election,” Pence said. “And, and this campaign and Donald Trump’s candidacy has been about the issues the American people care about.”

“But what about the negative side?” Stahl asked. But Trump jumped in.

“We’re different people,” Trump said. “I understand that. I’ll give you an example. Hillary Clinton is a liar. Hillary Clinton, that was just proven last week. Hillary Clinton — you better believe it. Hillary Clinton is a crook.”

Stahl tried to interject, but Trump continued to talk.

“I call her ‘Crooked Hillary.’ She’s crooked Hillary,” he said. “He wont. I don’t, I didn’t ask him to do it, but I don’t think he should do it because it’s different for him.”

Watch the excerpt.