Lyles, 24, came to Tokyo with a 2021 world-leading time of 19.74 set in the U.S. trials. He had been one of the pre-race favorites for gold, but came in third with Canada's Andre De Grasse winning in a time of 19.62 seconds.
The athlete said he was "proud" to represent his country, "but at the same time I want changes for my country."
"I think that's automatically a question of people being like, 'What does he mean by that?' Now you need to go and do research and figure out like what I've been saying for the past year," he said, "and of course that will drive the conversation forward."