US President Joe Biden has welcomed the conviction of Derek Chauvin and said it can be a "moment of significant change" after the white former police officer was found guilty of murdering 46-year-old black man George Floyd.

A jury unanimously convicted 45-year-old Chauvin of second-degree murder, third-degree murder and second-degree manslaughter after 10-and-a-half hours of deliberations over two days.

Mr Biden said Mr Floyd's death was "a murder in full light of day, and it ripped the blinders off for the whole world" to see systemic racism.

But he added: "It's not enough. We can't stop here. We're going to deliver real change and reform.

"We can and we must do more to reduce the likelihood that tragedies like this will ever happen again."

Sky's Greg Milam said Chauvin - whose face was obscured by a Covid face mask - showed little emotion as the guilty verdicts were read out and faces 12 and a half years in prison as a first-time offender, but prosecutors could seek a maximum of 40 years if the judge determines there are aggravating factors.

He put his knee on Mr Floyd's neck for nine minutes and 29 seconds while arresting him last year for allegedly trying to use a fake $20 note to pay for a pack of cigarettes.

Crowds erupted into cheers and applause outside the court building in Minneapolis following the conviction.

Mr Biden and vice president Kamala Harris spoke with Mr Floyd's family moments after Chauvin was remanded in custody, handcuffed and led out of the courtroom.

The president said: "Nothing is going to make it all better, but at least now God there is some justice."

But he also admitted that "such a verdict is also much too rare".

Mr Floyd's brother Philonise told reporters after the verdicts: "We are able to breathe again."

But he added the fight for justice was not over: "We have to protest because it seems like this is a never-ending cycle."

Mr Floyd's nephew Brandon Williams told crowds: "We need police reform bad.

"We need each and every officer to be held accountable and until then it's still scary to be a black man and woman in America."

The jury's decision was hailed around the country - and the world - as justice by politicians, civic leaders and celebrities.

Former president Barack Obama tweeted: "Today, a jury did the right thing. But true justice requires much more.

"Michelle and I send our prayers to the Floyd family, and we stand with all those who are committed to guaranteeing every American the full measure of justice that George and so many others have been denied."

Inaugural poet Amanda Gorman posted: "A reminder that victory would be George Floyd being alive. Every day Black Americans worry if they will be next is another day without justice."

California Governor Gavin Newsom, a white man, wrote on Twitter that Mr Floyd "would still be alive if he looked like me. That must change".

British Prime Minister Boris Johnson said he was "appalled" by Mr Floyd's death and welcomed the verdict.

Video footage of Mr Floyd's death on 25 May 2020, in which he cried he could not breathe, sparked a wave of anti-racism protests across the world, including the UK, with many marching through towns and cities under the banner of the Black Lives Matter movement.

Among those gathered outside the court on Tuesday was Mr Floyd's girlfriend Courteney Ross.

She told Sky News: "I miss Floyd so much you know, it's hard to think about how I feel. But I do know that I'm really hopeful for change right now.

"I feel like this has just opened up a door for so many people to have their cases reopened, to have people get justice for their lost loved one."