Greta Thunberg can certainly count Arnold Schwarzenegger among her growing list of celebrity fans after the pair went biking together and the actor lent the teenage activist his electric car.

The action star and former California Governor posted pictures of their meeting to his Instagram page, showing the pair on a bike ride around Santa Monica and meeting his daughter Christina.

He wrote: 'It was fantastic to see my friend and one of my heroes @gretathunberg last week and go on a bike ride around Santa Monica together and I was so pumped to introduce her to my daughter Christina. Keep inspiring, Greta!'

Their day out comes after the 16-year-old also met with Leonardo DiCaprio.

In May Greta opened the 2019 Austrian World Summit of non-profit environmental organisation R20 Regions of Climate Action, set up by vegan Arnie in 2011.

Backed by the United Nations, R20 is a coalition of governments, international organisations and private companies that implement green infrastructure in cities.

Arnold Schwarzenegger went on a bike ride around Santa Monica with teen Greta Thunberg

The former California Governor posted pictures of their meeting to his Instagram page

He wrote: 'It was fantastic to see my friend and one of my heroes @gretathunberg last week and go on a bike ride around Santa Monica together and I was so pumped to introduce her to my daughter Christina. Keep inspiring, Greta!'

Oscar winning actor Leo - who has been widely criticized for his use of private jets despite his interest in environmental causes - said it was an 'honor' to speak with the climate activist, posting an image of the two of them together on Friday.

In an Instagram post the actor said he hopes Greta's message is 'a wake up call to world leaders', adding that the schoolgirl makes him 'optimistic about what the future holds'.

Thunberg had made it half-way from Sweden to Chile by boat, train and electric car when next month's UN climate summit was unexpectedly scrapped and moved to Spain.

'As #COP25 has officially been moved from Santiago to Madrid I'll need some help,' Thunberg tweeted from Los Angeles. 'It turns out I've traveled half around the world, the wrong way:)'

'Now I need to find a way to cross the Atlantic in November... If anyone could help me find transport I would be so grateful,' said the teen, who refuses to fly because of the carbon emissions involved.

Leonardo DiCaprio says he hopes Greta Thunberg's climate change message is a 'wake-up call to world leaders', after meeting with the 16-year-old on Friday, pictured

Climate activist Greta Thunberg speaks at the R20 Austrian World Summit in Vienna in May

Thunberg's journey has so far involved crossing on a zero-emission sailboat from the coast of England to New York, traveling overland through North America by train and in an electric car borrowed from Arnold Schwarzenegger. The actor and Greta are pictured In May

Thunberg's highly publicized journey has so far involved crossing on a zero-emission sailboat from the coast of England to New York, traveling overland through North America by train and in a Tesla borrowed from Schwarzenegger.

She was one of around 25,000 delegates expected in Santiago for the United Nations climate summit, until Chile pulled out as host this week due to deadly anti-government protests.

The United Nations announced Friday that COP 25 will finally take place in Madrid, on the original scheduled dates of December 2-13.

The Swedish teen activist Thunberg rose to prominence last year after she started spending her Fridays outside Sweden's parliament, holding a sign reading 'School strike for climate.'

Students across the world began emulating her campaign, leading to organized school walkouts and the rise of the 'Fridays for Future' movement which targets government action on climate change.

She recently met with Ellen DeGeneres, telling the TV host it would be 'a waste of time' meeting with Donald Trump.

Ellen described Greta as 'real and raw' during filming for her show in California last Friday.