THE US Army has been asked to put military police units on standby after widespread protests struck Minneapolis over the death of George Floyd.

Soldiers from North Carolina and New York have been told to be ready to deploy within four hours as authorities look to quell disorder across a number of US cities.

Protests over the death of Lloyd, who had a knee pressed into his neck while being detained, have descended into looting and arson in some areas.

The get-ready orders were sent verbally on Friday, after US President Donald Trump asked defence secretary Mark Esper for military options to help quell the unrest in Minneapolis.

The National:

Police officer Derek Chauvin, 44, was charged with third-degree murder and second-degree manslaughter after the death of Floyd, who begged for air while being arrested on Monday.

Last night crowds gathered near the White House waving photographs of Floyd and chanting "I can't breathe", invoking his last words. The area was temporarily put on lockdown. 

A source said the military units would be deployed under the Insurrection Act of 1807, which was last used in 1992 during the riots in Los Angeles that followed the Rodney King trial.

The National:

Brad Moss, a Washington DC-based lawyer who specialises in national security, said: "If this is where the president is headed response-wise, it would represent a significant escalation and a determination that the various state and local authorities are not up to the task of responding to the growing unrest."

Members of the army's police units were on a 30-minute recall alert early on Saturday, meaning they would have to return to their bases inside that time limit in preparation for deployment to Minneapolis inside of four hours.

Units at Fort Drum are slated to head to Minneapolis first, according to the three people, including two Defence Department officials who wished to remain anonymous, and roughly 800 US soldiers would deploy to the city if called.

Rioters set fire to the Minneapolis Third Police Precinct near where Floyd was arrested yesterday and Mayor Jacob Frey ordered a citywide curfew at 8pm.

The National:

The unrest has since spread across the country with protests, some violent, erupting in cities including Washington DC, Atlanta, Phoenix, Denver and Los Angeles.

Minnesota Governor Tim Walz ordered 500 of his National Guard troops into Minneapolis, St Paul, and surrounding communities.

But a Pentagon spokesman said Walz did not ask for the Army to be deployed to his state.