"I won't traffic in fear and division,"Biden said."I won't fan the flames of hate. I'll seek to heal the racial wounds that have long plagued our country,not use them for political gain. I'll do my job and I'll take responsibility – I won't blame others."

Responding to Trump's brandishing of a Bible outside St John's Episcopal Church,just metres from the White House,Republican senator Ben Sasse said:"There is no right to riot,no right to destroy others’ property and no right to throw rocks at police.

"But there is a fundamental – a constitutional – right to protest,and I’m against clearing out a peaceful protest for a photo op that treats the word of God as a political prop."

Washington Archbishop Wilton Gregory criticised Trump's decision to follow up that visit with an appearance at a shrine honouring Pope John Paul II on Tuesday.

"I find it baffling and reprehensible that any Catholic facility would allow itself to be so egregiously misused and manipulated in a fashion that violates our religious principles,which call us to defend the rights of all people,even those with whom we might disagree,"Gregory said in a statement.

Responding to the President's threat to deploy the military in US cities against the wishes of state governors,Martin Dempsey,the former head of the Joint Chiefs of Staff,said:"America is not a battleground. Our fellow citizens are not the enemy."

In an open letter,former president George W. Bush said he and wife Laura were"anguished by the brutal suffocation of George Floyd"by a Minneapolis police officer who pressed his knee into Floyd's neck for more than eight minutes last week.

"It remains a shocking failure that many African Americans,especially young African-American men,are harassed and threatened in their own country,"the 43rd president said.

Barack Obama is expected to address police violence in a live-streamed conversation at 5pm American standard time (7am AEST),according to the Obama Foundation. He will"discuss the tragic events of recent weeks,the history of police violence in America,and specific action steps needed to transform a system that has led to the loss of too many lives".

The state of Minnesota has announced a civil rights investigation into Floyd's death. Governor Tim Walz and Human Rights Commissioner Rebecca Lucero said they hoped to reach agreement with the city to identify short-term ways to address the police department's history of racial discrimination,and use the investigation to find long-term solutions for systemic change.