President Donald Trump has derided the nation's governors as "weak" and demanded tougher crackdowns on protesters in the aftermath of another night of violent protests in dozens of US cities.
Mr Trump spoke to governors on a video teleconference with law enforcement and national security officials, telling the local leaders they "have to get much tougher" amid nationwide protests and criticising their responses.
"Most of you are weak," Mr Trump said.
"You have to arrest people."
The days of protests were triggered by the death of George Floyd, a black man who died after he was pinned at the neck by a white Minneapolis police officer.
They turned violent in several cities, with looting and mayhem, and fires ignited in the historic park across from the White House.
US attorney general Bill Barr, who was also on the Monday call, told governors they have to "dominate" the streets and control, not react to crowds, and urged them to "go after troublemakers".
During a protest in Washington DC, Mr Trump was rushed to a White House bunker on Friday night by Secret Service agents as hundreds of people protesting against the death of Mr Floyd gathered outside the executive mansion, some of them throwing rocks and tugging at police barricades.
Mr Trump spent nearly an hour in the bunker, which was designed for use in emergencies like terrorist attacks, according to a Republican close to the White House who was not authorised to publicly discuss it and spoke on condition of anonymity.
The source's account was confirmed by an administration official who also spoke on condition of anonymity.
The abrupt decision by the agents underscored the rattled mood inside the White House, where the chants from protesters in Lafayette Park could be heard all weekend and Secret Service agents and law enforcement officers struggled to contain the crowds.
Friday's protests were triggered by the death of Mr Floyd, a black man who died after he was pinned at the neck by a white Minneapolis police officer.
The demonstrations in Washington turned violent and appeared to catch officers by surprise, sparking one of the highest alerts on the White House complex since the September 11 attacks in 2001.
"The White House does not comment on security protocols and decisions," said White House spokesman Judd Deere, while the Secret Service said it does not discuss the means and methods of its protective operations.
The president and his family have been shaken by the size and venom of the crowds, according to the Republican source.
It was not immediately clear if First Lady Melania Trump and the couple's 14-year-old son, Barron, joined the president in the bunker, though Secret Service protocol would have called for all those under the agency's protection to be in the underground shelter.
"These were the people that trashed Seattle years ago. Who's paying for these people. I was appalled that 13 of Joe Biden's staff were donating money to bail people out in Minneapolis. They should have stayed in jail until this is over (and beyond)." @newtgingrich@foxandfriends
- Donald J. Trump (@realDonaldTrump) June 1, 2020
Mr Trump travelled to Florida on Saturday to view the first manned space launch from the US in nearly a decade.
He returned to a White House under virtual siege, with protesters, some violent, gathered just a few hundred yards away through much of the night.
Demonstrators returned Sunday afternoon, facing off against police at Lafayette Park into the evening.
As cities burned night after night and images of violence dominated television coverage, Mr Trump's advisers discussed the prospect of an Oval Office address in an attempt to ease tensions.
But the notion was quickly scrapped for lack of policy proposals and the president's own seeming disinterest in delivering a message of unity.
In recent days security at the White House has been reinforced by the National Guard and additional personnel from the Secret Service and the US Park Police.
On Sunday, the Justice Department deployed members of the US Marshals Service and agents from the Drug Enforcement Administration to supplement National Guard troops outside the White House, according to a senior Justice Department official who spoke anonymously.