Progress on racism in the United States is not going to happen immediately, says American four-time Olympic champion Michael Johnson.
Protests have been widespread in the US in recent months following a number of high-profile deaths of black Americans at the hands of police, including George Floyd and Breonna Taylor.
Johnson says the Black Lives Matter movement has made people “wake up”.
But he believes the progress made in 2020 “is only the start”.
“We are seeing progress,” the 53-year-old former sprinter told BBC Radio 5 Live. “But that progress, and we have to be very careful with the word progress, this is progress in what will be a generational fight.
“This is not going to change - it’s been hundreds of years of systemic and institutionalised racism, and what we’ve seen over the last four or five months is only a start.
“The Black Lives Matter movement is highlighting the racism and it is taking the first step. It has done a phenomenal job of getting people, even myself, to sort of wake up and see that what we thought, the progress that we have made has been phenomenal, but it is far from over.
“There is still a tremendous amount of work to do because there is a tremendous amount of racism that we didn’t even know exists that is affecting black people every single day that must be rectified and that is going to take a very, very long time.
“We have to be conscious of that and we cannot get frustrated. And we cannot expect like everything else that we have or we experience these days, with the advancement of technology and all of the innovation, where everything that we want we get immediately. This is not going to happen that way.”
Michael Johnson was speaking on the Adrian Chiles Show on BBC Radio 5 Live - listen to the full interview from 11:35 BST.