The US presidential election will "change America" and have "consequences for the world for 40 years", Cher has said.
The musician labelled Republican presidential candidate Donald Trump "dangerous" and "terrific at lying", while also suggesting younger generations struggle to trust Democrat Hillary Clinton.
"I don't know how he's a candidate, he is so dangerous, and what he brings to my country, what he's awakened in my country, is bigotry and distrust and a certain kind of supremacy in certain groups, and he lies.
"He's amazing, he tells something and then you go back and see what he's said and it seems like the truth both times, he's so terrific at lying. I've never seen anyone so good, it's amazing. I could go on and on on this subject forever because I'm so traumatised by him. I am truly traumatised by him."
Cher, speaking at the One Young World Summit in Ottawa, Canada, did not reserve her criticism just for Mr Trump.
"It's not easy, because especially millennials - they're not drawn to Hillary; they don't trust her, they feel that her sins are really enormous," she said.
"If you delve into some of the things she's being accused of - she's screwed up and that's for sure.
"But I've known her for a long time and I think that she will do her best. And she's a politician but she will do her best. If you look at her from the beginning of her life till now, she's worked hard for people."
The Oscar-winning actress, 70, was launching a campaign to free animals in captivity, but could not help lending her thoughts on the upcoming election.
She added: "What they need to know is that this election will change America and have consequences for the world for 40 years and the people who will suffer the most are millennials.
"And they will suffer because the people he will bring with him will put an end to any hope that women have of getting the rights we had in Roe v Wade. I believe they will put an end to any gay marriage. They will put an end to gay adoption. They will put an end to so many services that we do for the old, the young, the starving.
"They're the GOP (Republican Party). They're not the government of the people. And how he's able to align himself as one of the people is just, it's amazing, he really deserves some sort of reward, it's just amazing.
"I would say that it has such far-reaching consequences and - look, it's not going to hurt me, I'm 70, it's not going to do anything to me - it's going to do stuff to young people and that really scares me and it bothers me."
The global superstar launched her new campaign to ensure animals in captivity are treated and fed properly, and with "dignity".
Cher, a long-time anti-war and LGBT rights activist, was inspired to take up the cause of Kaavan the elephant after being made aware of the animal's plight through Twitter.
"This elephant was chained his whole life and never allowed to move," she said.
Her involvement in the campaign, and especially her influence on social media, eventually meant Kaavan was freed. He now lives in a sanctuary in Burma.
"I think that how we treat animals, how we treat children, how we treat old people, says everything about us," Cher said.
Despite the success of the campaign to free Kaavan, Cher now feels more voices are needed to make sure animals around the world in similar situations receive help, which is why she has launched the as-yet unnamed campaign.
"When I was young we were protesting everything, but mostly we protested the Vietnam war.
"We started out as a very small group and we were waiting for people to come together, and then people did come together.
"One person's voice is ... you have to keep doubling it exponentially you know, you have to have someone start it and then you have to have other people pick it up."
She added: "Donald Trump's sons, there's a picture of them holding a dead leopard. And I think that when that kind of message is sent from people who are influential, it's the exact wrong message. It changes the mindset of people, they become numb to what's going on.
"I just want to say if you have a pet ... just think about what would happen if that pet was mistreated, if that pet was tied up for its entire life and never allowed to move, you would be motivated to do something.
"I know that it's not foremost in your minds, but it doesn't mean that it's not important."