Justin Timberlake has stepped in to host a Hillary Clinton fundraiser after Leonardo DiCaprio had to pull out.

A source told PEOPLE: "Leonardo DiCaprio was scheduled to host a fundraiser with Hillary Clinton on Tuesday at his home in LA.

Unfortunately, Leo is stuck in New York until Wednesday to finish his current project.

"Not wanting to leave Hillary hanging, Leo called his friends Justin and Jessica Biel and asked if they would host for him. They immediately agreed to fill in as hosts and moved the event to their home for Tuesday."

Leonardo is currently producing climate change documentary 'The Turning Point', which features US President Barack Obama, Hillary's husband and former US President Bill Clinton, Secretary of State John Kerry, United Nations Secretary-General Ban Ki-moon and Pope Francis.

Earlier this year Leonardo spoke out about climate change as he took home his first Academy Award, calling it "most urgent threat facing our entire species".

He said: "I just want to say this. Making 'The Revenant' was about man's relationship to the natural world. A world that we collectively felt in 2015 as the hottest year in recorded history. Our production needed to move to the southern tip of this planet just to be able to find snow.

"Climate change is real; it is happening right now. It is the most urgent threat facing our entire species, and we need to work collectively together and stop procrastinating. We need to support leaders around the world who do not speak for the big polluters, but who speak for all of humanity, for the indigenous people of the world, for the billions and billions of underprivileged people out there who would be most affected by this.

"For our children's children, and for those people out there whose voices have been drowned out by the politics of greed. I thank you all for this amazing award tonight. Let us not take this planet for granted. I do not take tonight for granted."