Actress Jane Fonda has cast her lot in with Bernie Sanders, with an endorsement of the Vermont senator in his bid for the Democratic nomination.

The 82-year-old cited Mr Sanders’ commitment to fighting climate change, and said he is the only candidate who can take on that global crisis.

“We have to get a climate president in office, and there’s only one right now, and that’s Bernie Sanders,” Fonda told USA Today.

She then added, before attending a climate protest in Los Angeles: “So, I’m indirectly saying I believe you have to support the climate candidate.”

Fonda, a two-time Oscar winner, has become a well known and regarded figure among climate change protesters, and has been seen getting arrested while at demonstrations previously.

Mr Sanders, for his part, has included the Green New Deal — first introduced by Alexandria Ocasio-Cortez in Washington — to call for a transition to renewable energies and an end to “the greed of the fossil fuel industry.”

The democratic socialist faces an uncertain path to the Democratic nomination, however, after it appeared early in the primary season that he might amass a massive delegate lead against a fractured opposition.

But, after Joe Biden won the South Carolina primary, the former vice president managed to consolidate support among moderate Democrats, and outperformed expectations on Super Tuesday.