Adams played in all three of South Africa's group games at the tournament, up against co-hosts Mexico, Czechia and South Korea in Group A, with Bafana Bafana eventually being eliminated in the Round of 32 knockouts by Canada.
The sad news was confirmed by an official source in South Africa as per of an update that has shocked the country.
"It's with profound shock and a heavy heart that I have learnt of the passing of Jayden Adams," South Africa's minister of sport, arts and culture Gayton McKenzie said, in a statement.
"South African football has lost one of its brightest young talents, and our nation mourns alongside his family, his teammates and the millions of supporters who watched him grow from a promising academy prospect into a full Bafana Bafana international."
Further updates are expected in due course, and local police have confirmed an open investigation after the body of a 25-year-old man was found at a house in Schotschekloof, a suburb in central Cape Town, on July 11.
McKenzie added: "The cause of Jayden's passing has not yet been confirmed, and I wish to appeal to members of the media and the public to exercise restraint and compassion, and refrain from speculation, while his family and Mamelodi Sundowns are given the space and privacy they need at this incredibly difficult time."