William then confirmed he and Kate would be heading to the US in the coming months, telling viewers they "are so excited to be coming to Boston in December".
It's unclear if the couple will bring their three children to the States, though their eldest Prince George and Princess Charlotte have been attending more and more public events.
William also made a brief reference to his children in the message, adding: "The 2021 cohort of Earthshot Winners and Finalists is evidence that we can succeed, that we can protect our world for our children, our grandchildren and the generations that will follow them."
Now that William has confirmed that he and Kate will be travelling to the US in December, royal watchers are eager to see if he will reunite with brother Prince Harry there.
Prince and Princess of Wales to their California home while they visit the states.
The couple have been living there with their two children, Archie and Lilibet, since 2020 and have received other royal guests there, specifically Harry's cousin Princess Eugenie.
A reunion between the two brothers at Harry's new home could do much in healing the rumours of an ongoing "rift" between the brothers, and between Harry and the extended royal family.
The Duke of Sussex appeared alongside his brother at the Queen's funeral this week and previously visited the UK for her Platinum Jubilee and the funeral of Prince Philip in 2021.
WATCH BELOW: King Charles, Prince William and Prince Harry march at the Queens funeral
The story originally appeared on our sister site, Now to Love.