Singer and former Celebrity Apprentice star Cyndi Lauper said she is "shocked" by Donald Trump's inflammatory language, and compared the Republican presidential nominee to Adolf Hitler.

"That guy is selling inflammatory things that I have never in my whole entire life heard … except, you know, Hitler," the "Girls Just Want to Have Fun" singer said during a Friday radio interview on San Diego's Morning News. "A reality show is not a credential to be president."

Lauper, who opposed North Carolina's transgender "Bathroom Bill" earlier this year, said she is horrified by what she described as Trump's repeated bigoted remarks towards the LGBT community.

"And the things that he says are appalling to me and shocking. I was so shocked when he started to talk about the LGBT community … when in fact, people working who did amazing work on his Celebrity Apprentice show were gay," she argued. "You don't talk about your employees like that ever," said Lauper, who was one of the contestants on the reality television show in 2010.

In April, Trump took Lauper's side on the North Carolina law, and said people should be able to use whatever bathroom they want.

"There have been very few complaints the way it is. People go. They use the bathroom that they feel is appropriate," Trump said.

"That's not a great boss, even as a boss you have a responsibility for people who work for you."

Lauper, who has previously campaigned for the Democratic Party, said she no longer recognizes the party of Lincoln.

"It's pretty shocking. I don't know what happened to the Republican party," she said. "There used to be a Republican Party, but it's not anymore. And Lincoln was the first Republican — Abraham Lincoln. Let's just put it in perspective."