The Pentagon has moved about 1,600 US Army troops into the Washington DC region after eight consecutive nights of protests against racism and police brutality.
President Donald Trump has repeatedly raised the prospect of a military or national guard response to protests following the death of an African American man George Floyd in Minnesota police custody.
"Active duty elements are postured on military bases in the National Capital Region but are not in Washington DC," Pentagon spokesman Jonathan Rath Hoffman said in a statement.
He said the troops were on "heightened alert status" but "are not participating in defence support to civil authority operations."
Thousands of demonstrators gathered outside the US Capitol, chanting "silence is violence" and "no justice, no peace," as peaceful protests against police brutality swelled in major cities on Tuesday.
In Washington DC, where President Donald Trump promised to send in the military to deal with curfew-breakers on Monday, the demonstrators appeared undeterred, marching towards the White House in what many believed to be record numbers.
The peaceful protesters showed no signs of leaving as they approached DC's 7pm curfew, which thousands also defied the night before despite the president's warnings.
Protesters in several cities massed peacefully in large numbers on Tuesday including in Los Angeles, Washington and Philadelphia.
In New York City, thousands held an orderly march up 86th Street, followed by hundreds of club-carrying police on foot and police cars. President Donald Trump said on Tuesday the National Guard should patrol New York City's streets to put an end to fires, looting and property destruction.
In Floyd's hometown of Houston, thousands gathered for a march that was organised by Floyd's friends and family. On Hollywood Boulevard in Los Angeles, hundreds of people filled the street from curb to curb.
Despite the protesters' renewed determination, the President claimed his show of military and police force was a success.
"DC had no problems last night. Many arrests. Great job done by all," he tweeted.
"Overwhelming force. Domination. Likewise, Minneapolis was great (thank you President Trump!)."
First Lady Melania Trump, also took to Twitter to urge people to obey the curfews and call for "healing and peace".
"As the night approaches, I urge all citizens to obey the curfews, clear the streets and stay inside to spend time with loved ones," she tweeted.
"All cities, communities and citizens deserve to be kept safe and that can only be done if we work together towards healing and peace."
Mr Trump earlier said troops should take to the streets of New York City, while elsewhere five officers were shot and wounded as police clashed with protesters nationwide.
Demonstrators smashed windows and looted stores in New York City late on Monday and set fire to a Los Angeles strip mall amid widespread protests over the killing of an African-American man in police custody.
Four officers were shot and wounded in St Louis, Missouri, and one in Las Vegas was critically wounded, authorities said on Tuesday.
Mr Trump has threatened to use the military to battle the violence that has erupted often at night after a day of peaceful protests joined by a cross-section of Americans.
He has derided local authorities, including state governors, for their response to the disturbances.
"NYC, CALL UP THE NATIONAL GUARD. The lowlifes and losers are ripping you apart. Act fast!" Mr Trump tweeted on Tuesday.
New York Governor Andrew Cuomo voiced outrage at the chaos in America's largest city, saying its mayor and police force "did not do their job last night".
He said he believed Mayor Bill de Blasio underestimated the scope of the problem.
Mr Cuomo said he had offered mayors support from state police or 13,000 National Guard who are on stand-by and said that with a 38,000-strong police force, New York City should be able to address its unrest on its own.
Mr De Blasio poured cold water on the idea of bringing the National Guard to America's largest city.
Meanwhile the owner of a popular barbecue spot who was fatally shot by police in Louisville, Kentucky, had fired a gun as officers approached, the city's acting police chief said.
Acting Police Chief Robert Schroeder said security camera footage showed David McAtee opening fire while officers were trying to clear a crowd from a car park on Monday.
Demonstrators kneel in Los Angeles during a protest over the death of George Floyd. Source: AP
Mr Schroeder said police were releasing the video to provide transparency.
"It does not answer every question, including why did he fire and where were police at the time he fired?" he said on Tuesday.
The Louisville police chief was fired after it was revealed officers involved in Mr McAtee's shooting had failed to activate their body cameras.
In St Louis, four officers were recovering after being shot overnight amid clashes between police and crowds throwing rocks and other projectiles.
Demonstrators run from tear gas used by police to clear the street near the White House in Washington. Source: AAP
And a police officer was shot during protests in Las Vegas, police there said in a statement.
Officers were injured in clashes elsewhere, including one who was in critical condition after being hit by a car in the Bronx.
In Atlanta, six officers will face charges for an incident in which two college students were removed from their car and tasered, Fulton County District Attorney Paul Howard told a briefing.
Two of the six officers were let go on Sunday.
And a police officer in Sarasota, Florida, was placed on leave on Tuesday after video surfaced showing the officer kneeling on a man's back and neck during an arrest in May.
The violent US protests were triggered by the death of George Floyd, a 46-year-old African-American who died after a white policeman pinned his neck under a knee for nearly nine minutes in Minneapolis on May 25.
Minneapolis police officer Derek Chauvin, 44, has been charged with third-degree murder and second-degree manslaughter.
Three other officers involved have not been charged.
