Transcript for John McCain reads passionate excerpt from memoir

We have now a powerful message from senator John McCain speaking candidly about his battle with brain cancer, his hopes for our country and the divisions holding us back, the first excerpts of his final book and Mary Bruce joins us with the details. Good morning, Mary. Reporter: Good morning, George. Well, for the first time in months we're hearing directly from senator John McCain in these first clips of his new member wafrment the senator known for his straight talk is at it again. He sounds prepared for whatever may come next and as a powerful message about the future of our country. Senator John McCain in his own words. I don't know how much longer I'll be here. Reporter: That familiar voice. Reporter: Maybe I'll have another five years. Maybe I'll be gone before you hear this. Predicament is, well, rather unpredictable. Reporter: In his plain-spoken style, the 81-year-old is reflective and blunt as he battles brain cancer. I want to talk to my fellow Americans a little more if I may. Reporter: In his new memoir, "The restless wave," out later this month, McCain celebrates the country he's spent his life serving. We can be selfish and quick sometimes to shift the blame for our mistakes to others, but our country 'tis of thee, what great good we've done in the world. So much more good than harm. Reporter: But he doesn't hold back either criticizing president trump saying his lack of empathy for refugees, innocent, persecuted, desperate men, women and children is disturbing. And he makes a passionate plea for civility. Before I leave I'd like to see our politics begin to return to the purposes and practices that distinguish our history from the history of other nations. I'd like to see us recover our sense that we're more alike than different. Reporter: After more than 30 years in the senate he announced this will be his last term. He remains at home in Arizona in stable condition recovering from the side effects of his cancer treatment. As for what comes next -- I want to smell the rose scented breeze and feel the sun on my shoulders. I want to watch the hawks hunt from the sycamore and then take my leave. Reporter: Now that new book comes out later this month on may 22nd and while we haven't seen John McCain up here on the hill since late last year, he is still actively involved in all of the goings on here making his points of view well known putting out statement, sending out those tweets, George, his presence is still very much felt here in these halls. Eloquent using every moment every way he can. As we would expect. Just to hear his voice, our country 'tis of thee.

This transcript has been automatically generated and may not be 100% accurate.