John McCain says in new biopic: 'I'm a human being and I'm not a maverick'

This Memorial Day, HBO is releasing "John McCain: For Whom the Bell Tolls," a documentary featuring extensive interviews with the 81-year-old Republican senator.

McCain, who is battling brain cancer, is seen on camera serenely reflecting on his life, from his time as a POW in Vietnam to his three decades of service in the U.S. Senate, in interviews filmed at his home in Sedona, Arizona.

"I've been tested on a number of occasions. I haven't always done the right thing ... but you will never talk to anyone who's as fortunate as John McCain," McCain said in a trailer for the documentary provided to ABC News.

The documentary features dozens of interviews with McCain, his wife and children, and close friends including Sen. Lindsey Graham, former Sen. Joe Lieberman, former Secretary of State Hillary Clinton and several former presidents.

In a clip provided exclusively to ABC News, McCain describes the moment his doctors revealed to him the life-threatening diagnoses.

"Just tell me, just tell me, that's all I want to know," said McCain, revealing he implored his doctors to be upfront about the cancer.

The documentary was produced and directed by six-time Emmy winner Peter Kunhardt, along with Emmy winners George Kunhardt and Teddy Kunhardt.

In an interview with ABC News, Teddy Kunhardt described meeting with McCain in Sedona just three weeks after the senator was diagnosed with a glioblastoma, a form of brain cancer.

McCain told Kunhardt he had two conditions if he was going to participate in the documentary.

"He said," Kunhardt recalled, "there are two things I would like to accomplish: The first is, I want the American people to know I'm a human being and I'm not a maverick, and I have made mistakes. And I want you to tell my story in an honest way."

"We didn't want an obituary piece. We wanted them to talk about the person they love and respect, and that was a conscious decision to get them right away, so we filmed 26 interviews in 2 months," Kunhardt said. And "there was nothing that we couldn't ask about."

Kunhardt said the biggest thing he hopes viewers take away from the documentary is that McCain is an "amazing American."

"John is an amazing American that has dedicated his life to service -- the first half of his life in the military, the second half of his life in government," Kunhardt said. "And, yes, he's screwed up and he has made big mistakes, but he's going to address those mistakes."

"John's willing to put country over party, which very few people are willing to do now," Kunhardt said.

The filmmaker discussed bipartisanship with the senator.

"I think he’s discouraged, I think he’s disappointed, but he has seen the American system work, and he knows it can work, and he knows it can work the best when they work together," Kunhardt said. "So I think he will continue to fight tooth and nail till his last breath to make sure this generation, my generation, knows that the system can work, and these guys and ladies have to stop being separate and come together and get things done."