The director of Leonardo DiCaprio’s documentary on climate change has claimed a Donald Trump victory in the US presidential election would be “the worst thing that could happen” for the environment.

Oscar-winner Fisher Stevens filmed Leonardo as he travelled around the world to see the effects of global warming for his latest feature, Before The Flood.

Stevens joined The Revenant actor at the documentary’s world premiere at the Toronto International Film Festival where he voiced concerns about Mr Trump’s views on climate change.

Leonardo DiCaprio (Ian West/PA)

The Republican nominee has previously claimed global warming is a hoax created by China and said he would “cancel” the Paris climate deal aimed at cutting carbon emissions.

Fisher told the Press Association: “Donald Trump would be the worst thing that could happen on the planet if he’s elected president.

“At least that’s what he says….you never know with Donald Trump. Right now, he says he won’t validate the Paris climate talks and he’s going to overturn all of the good things Obama has been doing.”

Leonardo DiCaprio and Fisher Stevens (Evan Agostini/Invision/AP)

Fisher, who produced the Oscar-winning documentary The Cove about dolphin hunting practices in Japan, said Leonardo, 41, approached him about making their latest film together.

Before The Flood follows Leonardo as he travels to a number of countries, visiting flooded streets in Miami Beach, smog-choked areas of Beijing and incinerated forests in Indonesia.

“We’re not doing this to get rich,” Fisher said.

While filming #BeforeTheFlood, @LeoDiCaprio sees – and hears – Arctic narwhals. Screen the film today at #TIFF16.

— Nat Geo Channel (@NatGeoChannel) September 9, 2016

“Leo certainly didn’t schlep around all over the world to enhance his career.

“I learnt the climate is actually in worse shape than I expected. I also learned we could fix it a lot easier than I thought. The way renewables and solar and wind are becoming more affordable, it’s all economics.”

DiCaprio’s long-time collaborator, director Martin Scorsese, is an executive producer on the Before The Flood.