Prince Harry has revealed Meghan Markle is "hugely excited" to be joining him in his Commonwealth work as he paid tribute to the Queen's service to the Family of Nations.
Harry described how the woman he will marry in just over a month would be by his side in his new role as Commonwealth Youth Ambassador, a post bestowed by the institution's head the Queen.
The prince's comments came as he helped open the Youth Forum, which launched the Commonwealth Heads of Government Meeting (Chogm) week, with a speech, and told the young delegates "it is you who are going to change the world".
Earlier he was joined by Prime Minister Theresa May at a roundtable discussion with young leaders, where both expressed their faith in the Family of Nation's youth.
During his speech, Harry got cheers and whoops from the audience when he mentioned his bride-to-be, who will join him on Wednesday at a Commonwealth Youth Forum reception.
The prince said: "In my new role, I will work to support the Queen, my father the Prince of Wales, and my brother William, all of whom know that young people are the answer to the challenges of today.
"I am also incredibly grateful that the woman I am about to marry, Meghan, will be joining me in this work, of which she too is hugely excited to take part in."
The US actress and Harry have already expressed their interest in the Commonwealth and it is widely anticipated they will go on a Commonwealth tour after their May 19 wedding.
Harry said he looked for inspiration for his new role from his grandmother the Queen and he highlighted her famous speech from 1947 where she pledged her life to the Commonwealth.
He said: "On the day of her 21st birthday, the then Princess Elizabeth gave an extraordinary radio address from Cape Town.
"With an eye on the future, and an already unflinching sense of duty, she made a commitment. She said that whether her life be long or short, it would be dedicated to the service of the people of the Commonwealth.
"All of us here today can be grateful that it is a long life the Queen is still enjoying. Her Majesty's commitment has meant that the Commonwealth is a thriving family of nations, a common link between nearly two-and-a-half billion people, and a defender of democracy, justice and peace."
Speaking at the Queen Elizabeth II conference centre in central London, Harry praised the next generation of the Commomnwealth: "You care. You want your nations to be cleaner, your planet to be greener, your friends and neighbours to be treated fairly and with respect, no matter their ethnicity, their religion, or their status.
"You are optimistic. The complicated challenges we face climate change, inequality, conflict they do not discourage you. Rather, they inspire you to persevere and effect change."
He added: "After all, 60% of the Commonwealth is under the age of 30. And at 1.4 billion strong, it is you who are going to change the world."
Earlier, Harry and the Prime Minister met members of the Commonwealth Youth Council and Youth Taskforce with the prince telling them "you guys have the answers" before he and Mrs May briefly joined their roundtable discussion.
The Prime Minister acknowledged that young people had helped set part of the agenda for the week with the environment and youth unemployment due to be discussed.
Sat around a table with Harry and the young delegates Mrs May told them: "It's great that this week of the Commonwealth Heads of Government Meeting is being kicked off by the Youth Forum because as you say, I wanted to make sure that youth, young people were the priority for this week's meetings.
"Because if you just look at the figures - I think it's young people under the age of 30 make up 60% of the Commonwealth population - you are the future of the Commonwealth.
"And it's important we listen to you, we hear your ideas, hear your areas of concern - and you've already shaped the agenda. A couple of the issues that you wanted to have discussed here at the head of government meeting - youth unemployment and the environment (are on the agenda)."
She said there would be discussions about how a young person gets the opportunity for a "good job" and a "good start in life" and looking at how the oceans can be protected.