Former vice president Joe Biden on Friday said he is "furious" over President Donald Trump "calling for violence against American citizens" during the protests in Minneapolis over the death in police hands of a black man, George Floyd.

"Enough," wrote Biden, the presumptive Democratic presidential nominee, in a tweet thread responding to Twitter posts from Trump.

The president early Friday, after a police precinct in Minneapolis was torched by protestors, wrote on Twitter that he was willing to send the National Guard to deal with the chaos, adding: "when the looting starts, the shooting starts.".

He called Floyd's death just the latest in a series of injustices stemming from racism against black people, which Biden said was the "original sin" of the United States, which "still stains" the nation.

"This is national crisis, and we need real leadership right now," Biden said. "We need justice for George Floyd.

Biden's earlier tweet thread referenced the arrest Friday morning on live television by Minnesota state police of Omar Jimenez, a CNN reporter who was covering the protests in response to Floyd's death. Jimenez soon after was released.

"This is not abstract: a black reporter was arrested while doing his job this morning, while the white police officer who killed George Floyd remains free.

Within hours of Freeman speaking, the Third Police Precinct in Minneapolis was overrun by protestors and set on fire.

But the party on Friday afternoon said it is postponing the speaking and training portion of the convention until an unspecified time due to the situation surrounding Floyd's death, which is called a "murder."

DFL Party Chairman Ken Martin in a statement said, "This was the only appropriate course of action given the grief and anger gripping much of our state and nation following the murder of George Floyd and the subsequent unrest sweeping the Twin Cities