Legendary civil rights activist, singer, and actor Harry Belafonte took the stage over the weekend at what he said would be his last public appearance and issued a stark warning about what he thinks may be in store for America.

Electing Donald Trump was a mistake, he said, "and I think the next mistake might very well be the gas chamber and what happened to Jews [under] Hitler is not too far from our door," the Guardian reports him as saying.

Ninety-year-old Belafonte, who recently said he thinks "the nation is at the crossroads of probably our most challenging moment in history," was speaking on "Civil Rights and Black Leadership" at the Carnegie Music Hall in Pittsburgh.

He talked about how his mother, a Jamaican immigrant, played a formative role in his fight for social justice. As Belafonte told a crowd in New Haven, Conn. days earlier, "She told me to never come across an injustice and not stop to fix it." Her message, he told the Pittsubrgh crowd, "stayed with me forever."

Despite his warnings about a Trump-era U.S., Belafonte still expressed reason for optimism.

"I think in the final analysis that we shall overcome, because what we did is … we left a harvest that generations to come [will] reap. That they have not yet plowed. That they have not yet harvested."

His warnings about President Trump are far from new.

Days before Trump took office, he said that "we, citizens of the union, have the capacity and the responsibility to make sure that Trump's philosophy and his view of life and fellow beings does not endure." And, he added, "I will spend what time I have left on this good earth to make sure that I have contributed all that's at my disposal to make him unworthy."

"It isn't just Donald Trump, the man or his villainy, his broken spirit or the corruption of his soul that is always a presence in our midst," he said ahead of Election Day. "It was startling to see the number of people who approved of him, who embraced him and who support his utterances. America has a cancer that's at work. It's slowly distributing itself through the national body."

To fight such forces, he thinks some "ass-kicking" is needed.

At a Democracy Now! event in December, he said "we might have fought to end Hitler, but we also fought for our right to vote in America, that in the pursuit of such rights came the civil rights movement. Well, that can happen again. We just have to get out our old coats, dust them off, stop screwing around and just chasing the good times, and get down to business. There's some ass kicking out here to be done. And we should do it."

Belafonte, whose advanced age was apparent at the Friday event, will leave a rich legacy of song, film, and advocacy to inspire future generations.

For his epitaph, though, he has suggested there should be just one word: "Patriot."