Sen. Bernie Sanders, I-Vt., blasted President Donald Trump on Thursday, calling him a "fraud" during an appearance on MSNBC's "Morning Joe."

"He has got to be exposed for the fraud that he is, not just focusing on his temperament and on his tweets, but on his extremely right-wing policy that is paid for by the Koch brothers and other billionaires," Sanders said.

The president's policy proposals are more dangerous than his tweeting habits, according to the Vermont senator, who ran for the Democratic presidential nomination in 2016.

"It's not just his temperament, it's not just his stupid tweets. Do not forget for a second that the policies that he is proposing are the most destructive policies being proposed in our lifetimes."

The president is not interested in helping voters in rural areas, despite his claims during his presidential campaign, he said.

"I hope that Trump supporters in rural states understand that when he told them during the campaign that he was going to stand up for working-class people was nothing but a lie."

The senator also discussed Trump in an interview released Thursday morning on Sirius XM's "Make It Plain With Mark Thompson," according to Newsweek.

"He is a representative of the billionaire class, he's at war against the working class," Sanders said.