United States President Joe Biden assured the cheering crowd in Detroit on Friday that he's not going to step down, warning that Republican rival Donald Trump is a big threat.

"I am running and we're going to win," he said to a crowd that carried "Motown is Joetown" signs and chanted, "Don't you quit."

"I'm the nominee," he said. "I'm not going anywhere."

Pointing to the press area in the gym, Biden said, "They've been hammering me," to which the crowd booed. "Guess what, Donald Trump has got a free pass," he added.

"Hopefully with age comes a little wisdom," Biden said, in a defiant and sometimes gleeful performance. "Here's what I know — I know how to tell the truth, I know right from wrong and I know Americans want a president, not a dictator."

Moreover, Biden put forth his plans for the first 100 days of the second term, including abortion rights, signing the John Lewis Voting Rights Act, ending medical debt, raising the minimum wage, and banning assault weapons.

Earlier on Friday, the Democrat made a surprise visit to a garage-themed restaurant and assured that he is okay and will finish the job.

Biden received endorsements from Democratic Representative James Clyburn and California Governor Newsom. Additionally, United Auto Workers President Shawn Fain praised Biden for supporting the working class.

Meanwhile, Democrats are worried about Biden’s low approval ratings, and age concerns that could have an impact on the forthcoming elections. However, Biden has been holding calls with various Democratic groups to strengthen his support base.