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.