Prince Harry is using a new phrase to usher in a fresh perspective on mental health.

The Duke of Sussex, 40, underscored the importance of mental health while speaking at the United Nations during his solo visit to New York City. Prince Harry joined Queen Masenate Mohato Seeiso of Lesotho on Sept. 24 for an event organized during the U.N. General Assembly High-level Week, where he advocated for “mental fitness” in his remarks during the intimate presentation. 

“Much of the work I undertake comes under the umbrella of mental health and our collective well-being. And the rising rate of suicide among young people in Lesotho, and around the world, weighs heavily on my heart, as I’m sure it does on yours too,” Prince Harry said in part.

“Good mental health, mental fitness, is not a luxury — it is a necessity for every single one of us. More so, perhaps, for our decision makers and those sitting in positions of power and influence,” he said. “Addressing this issue requires not only global action, but also the courage to break the stigma, to talk openly about our mental health without fear of judgment.”

Prince Harry’s sussex.com bio describes him as a “mental health advocate,” and he brings that focus to his charity Sentebale, which he co-founded with Prince Seeiso of Lesotho (who is Queen Masenate’s brother-in-law) in 2006 to help children and young people in Lesotho and Botswana. The organization works to support youth living with HIV/AIDS who are navigating mental health challenges, connecting back to what Harry said at the U.N.

The phrase “mental fitness” was first attributed to King Charles‘ son during the first event of his New York City trip on Sept. 23. On Monday, Harry appeared on the panel “The Global Mental Health Crisis Among Young People: A Conversation with Prince Harry, The Duke of Sussex and Dr Tessy Ojo CBE, CEO of the Diana Award” at the 2024 Concordia Annual Summit, where Ojo said that Prince Harry suggested that society should reframe “mental health” as “mental fitness.” 

“He actually said to me, as we came in, that actually, ‘We should no longer talk about mental health, we should talk about mental fitness,’ ” Ojo said in her opening remarks. “His dedication to this cause strengthens our mission.”

Prince Harry and his brother Prince William both support The Diana Award, the only charity established in memory of their late mother, Princess Diana, and firmly rooted in her belief that young people have the power to change the world. The late Princess of Wales’ sons each appeared (Harry virtually, and William in person) at a London event celebrating the Diana Award’s 25th anniversary in March, where they connected with the 20 Legacy Award winners from around the world.

Jamaica’s Christina Williams, 27, and Indonesia’s Chiara Riyanti Hutapea Zhang, 18, were among that cohort, and spoke alongside Prince Harry and Ojo on stage at the Concordia Summit. Speaking to PEOPLE after the panel discussion concluded, Williams said that it was a pleasure to meet Prince Harry, and further referenced the idea of “mental fitness.” 

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“I think he was very encouraging of us, saying that we’re going to go out there, we’re going to do a great job. He also spoke about the things that he was very passionate about, like the climate, trying to destigmatize mental health, bringing it down to a level of everybody’s business,” Williams told PEOPLE about what it was like to spend time with Prince Harry.

“It’s about mental health, but also about mental fitness and mental wellbeing. So I think that was really good to warm us up for the stage and just put us in a place where we just spoke from the heart,” she said.

The Duke of Sussex packed a busy schedule into his working trip to New York City, which was previously announced in August. His spokesperson said that he would visit New York “to advance a number of his patronages and philanthropic initiatives,” as well as his work with the Archewell Foundation, which runs with his wife Meghan Markle, during High-level Week and Climate Week in September. 

Prince Harry did just that, with outings around The Diana Award, The HALO Trust, African Parks and more. 

If you or someone you know needs mental health help, text “STRENGTH” to the Crisis Text Line at 741-741 to be connected to a certified crisis counselor.