Michael Moore attends the 'Farenheit 11/9' premiere during 2018 Toronto International Film Festival at Ryerson Theatre on September 6, 2018 in Toronto, Canada.

Filmmaker Michael Moore compares U.S. President Donald Trump to Adolf Hitler in his provocative new documentary, "Fahrenheit 11/9" that got its world premiere at the Toronto International Film Festival on Thursday to a sold-out audience.

The documentary examines the forces Moore believes contributed to Trump's election victory in November 2016, drawing parallels with the rise of Hitler in 1930s Germany.

The White House could not immediately be reached for comment on Thursday.

At one point, the film superimposes Trump's words over videos of Hitler's rallies, as a historian talks about the rise of strong men to positions of power.

"We explore the question of how the hell we got in this mess and how do we get out of it," the liberal activist told reporters ahead of the film's screening.

"He's (Trump) been around for a long time and we've behaved in a certain way for a long time and when you look back now you can see how the road was paved for him," Moore said.

The new film was a call to action for Americans, said Moore, who won an Oscar in 2003 for his gun violence documentary "Bowling for Columbine."

"We are in a war to get our country back," he said. "Anyone who doesn't understand that is going to be sorely disappointed in the results of what's about to happen in the next few years with Donald Trump."

"Fahrenheit 11/9" takes its title from the early hours of Nov. 9, 2016, when Republican candidate Trump was officially declared the victor over Democratic Party candidate Hillary Clinton.