Barack Obama has told young people of colour “your lives matter” in a public address he made at an event organised by his own Foundation. His supporters welcomed his intervention as an antidote to Donald Trump’s threats to crack down on civil unrest and dissent.

The former US President on Wednesday expressed faith in the young people of the country and said he remained “optimistic” about the future despite the police killing of George Floyd and mounting crises that Trump’s critics say leave the country crying out for leadership.

Obama spoke at an event by the My Brother’s Keeper Alliance, a program of the Obama Foundation, that was called “Reimagining Policing in the Wake of Continued Police Violence.”

It was the first public appearance by the 44th president since Floyd was killed by a white Minneapolis police officer kneeling on his neck.

The killing sparked nine days of nationwide protests with looters and anarchists mingling in with the peaceful crowds and causing chaos. Several people have been killed in the riots.