Prince George, Princess Charlotte and Prince Louis 'very upset' at not meeting Sir David Attenborough

Prince George, Princess Charlotte and Prince Louis were "very upset" not to meet Sir David Attenborough, according to their mum, the Duchess of Cambridge.

• The Duke and Duchess of Cambridge met Sir David Attenborough as part of the new ITV documentary, Prince William: A Planet For Us All
• Kate Middleton revealed their three children, Prince George, Princess Charlotte and Prince Louis, were not happy they weren't invited to meet the conservationist as they're "massive fans"
• In other royal news, Prince Harry and Meghan Markle made a rare TV appearance for the first time since leaving the UK

Kate Middleton has revealed her three children were very disappointed they didn't get to meet the national treasure, revealing the royal tots are "massive fans.

In a new clip to promote the ITV documentary, Prince William: A Planet For Us All, the Duke of Cambridge and his wife are seen meeting Sir David.

Prince William greets the conservationist, by saying, "Here's a recognised face."

As they shake hands, Kate reveals how George, Charlotte and Louis are gutted to not be in attendance.

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She says, "The children were very upset that we were coming to see you and they weren't coming. They're massive fans of yours!"

And David is heard, in a voiceover, saying how important children are to fighting climate change.

He says, "Kids know an awful lot about what's happening to the world."

In the trailer, William also reveals how having children has affected the way he thinks of climate change, saying, "I've always loved nature but fatherhood has given me a new sense of purpose.

"Now I've got George, Charlotte and now Louis in my life, your outlook does change."

Explaining why he's decided to make this documentary, he continues, "You want to hand over to the next generation. The wildlife in a much better condition.

"So two years ago a film crew joined me on my search for ways to protect the natural world."

Kate and Will's revelation about their kids' love of Sir David comes after they confessed they're very much into diggers too!

During a visit to a construction sight on a recent royal engagement, William revealed little Louis’ obsession with diggers.

“The children, especially Louis, would love to come and watch that, to see the diggers, they love it,” he said.

“Don’t forget Charlotte! She’d love it too,” Kate chipped in.

Prince William: A Planet For Us All will air on ITV and ITV Hub this October.