AUSTIN, Texas -- He was the first press secretary of the Trump White House. He tussled with the press – a lot. He admits he messed up.

Former White House Press Secretary Sean Spicer has a new book that highlights his highs and lows during his time in the Trump administration.

He was in Texas on Friday to tout his new book, “The Briefing: Politics, the Press, and the President.”

During an interview with Capital Tonight anchor Karina Kling, he said he thought his first day might be his last after his now infamous inaccurate claim that Trump’s inauguration had the “largest audience to ever witness an inauguration, period. Both in person and around the globe.”

“If I could have one day to do over in my life, I think that’s number one, two and three,” Spicer said.  

He said Trump did not push him to make that statement. Instead, Spicer said the president was not happy with him about his performance.

“I really worried that that day was going to be my last and I think that it really set the tone for a lot of things to come, which I don’t think was a helpful first step," Spicer said. 

Spicer also said he doesn’t know who wrote the anonymous New York Times op-ed attacking Trump.

“I can’t imagine anyone I worked with writing this,” Spicer said. “I don’t know who it is. I think the person who did is frankly a coward. If you don’t like the president, don’t work for him or speak out.

On the many exits from the Trump administration, Spicer said he would never characterize the atmosphere as dysfunctional. But he added it’s not traditional.

“There was a lot of people who I think were new and so a lot of it was churn. Some of it was the wrong fit. And some of it is just exhaustion,” Spicer said. “It’s an unbelievably intense place to work under any administration.”

Click the video link above to watch the full interview with Spicer, including his relationship with the press, defending Trump’s untruths and his take on Melissa McCarthy portraying him on "Saturday Night Live."