Charles said disruptions caused by the pandemic "have the potential to be devastating in their impact on young people's wellbeing".
He was delivering a message to mark International Youth Day on Friday, an occasion he said is "immensely close to my heart".
"Today gives us all an opportunity to celebrate the incredible achievements of young people and, additionally, allows us to reflect on the impact that recent years have had on the younger generation," the Queen's eldest son said.
"In terms of the adversities they have faced, it is remarkable to see the resilience and ambition young people continue to show in the face of unprecedented global challenges."
Charles said "it is time for us all to come together to support the world's future workforce" as the effects of climate change "loom large and are felt acutely".
He also spoke about his charity, the Prince's Trust, which has worked for many years to help young people with skills to find employment.
Recent research from the charity and Learning and Work Institute found the proportion of out of work young people in the UK reporting a mental health problem has increased from 11 per cent in 2011 to almost a third (30 per cent) in 2022.
"There has been much to erode the hope of the younger generation," Charles said.
"Sadly, from speaking to young people supported by my trust, I've heard how the pandemic has disrupted their crucial transitional years on the journey from school to work, and from childhood to adulthood.
"From leaving education without the camaraderie of their school friends to raise their spirits to learning new skills online, it is clear that many young people have experienced unique challenges during this formative period of their life.
"These disruptions have the potential to be devastating in their impact on young people's wellbeing and my trust has found time and time again that poor mental health can become a significant obstacle when young people try to take their next step into employment.
"Young people leaving education do not feel ready for the world of work.
"They are calling for us all to play our part and help provide them with the skills they need for the jobs of the future."
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