The Princess of Wales is doing “really well” and has been “amazing this whole year”, Prince William has said.
He was speaking to broadcasters ahead of presenting his environmental Earthshot Prize in Cape Town, South Africa later.
On his wrist the Prince of Wales was wearing a bracelet saying “Papa” made for him by his daughter Princess Charlotte for a Taylor Swift concert, which he said he had promised to wear on the trip and “try not to lose”.
His wife has not travelled to South Africa as she recovers after treatment for cancer and will instead be watching the ceremony at home in Windsor.
Catherine will be “cheering me on”, he said, adding: “I know she’ll be really keen to see tonight be a success.”
The bracelet was made by Charlotte for her father when they went to a Taylor Swift concert at Wembley.
Friendship bracelets have become synonymous with the pop star and her sellout Eras tour and are regularly swapped with fellow “Swifties” at her concerts.
Prince William was speaking to the BBC inside the eco “Super Dome” that has been built for this evening’s awards ceremony in Cape Town.
The eco dome will be recycled and reused elsewhere after the ceremony.
First awarded in 2021, the prize supports sustainable, eco-friendly projects from around the world, with five winners each receiving £1m.
There is a focus on ideas from Africa for this year’s event, with more than 400 African-led projects nominated and another 350 linked to the continent.
The Prince of Wales spoke of his affinity with Africa having spent time there on his gap year before university, volunteering on wildlife conservation projects in Kenya, Botswana, and Tanzania .
“I love this continent. I spent many a year looking around exploring it and just really thrilled to have the reception and exuberance and the energy that will be in this room tonight,” he said.
The ambition of the prince’s Earthshot Prize has been to bring hope and innovation to the most difficult environmental challenges.
When asked about achieving that in a tough political climate, the prince was positive.
“Everyone wants some hope and some optimism and Earthshot comes with urgent optimism,” he said.
Much of the prince’s visit to Cape Town this week has focused on young people and the power they have to bring about change.
“Without them the future is looking pretty bleak so these are the game-changers, the innovators, the inventors who are going to make the world a better place for us in future.”
This was something his own children, Prince George, Princess Charlotte and Prince Louis, were aware of, he added.
“Every family tries to do what they can to help with the environment and we go through the basics of recycling and making sure we minimise water use, turning lights off when you leave the house – we’re sensible with what we do around the environment. I think every family has those conversations.”
But he added that Earthshot had far bigger ambitions.
“We’re trying to do big scale ambition and business. I’ve brought the children along on that journey and I hope they’re proud of what we are trying to do here which is to galvanise that energy and enthusiasm to make real impact.”