President Trump on Sunday called for "law and order" as protests raged nationwide, urging local leaders to crack down against demonstrators while tensions remained high between them and law enforcement.

The president remained out of public view on Sunday, one day after protests turned violent in major cities across the country. Some allies urged him to deliver a formal address to the nation in an effort to build national unity, but Trump instead opted to lash out on Twitter and press for a show of force in response to the unrest.

"Get tough Democrat Mayors and Governors. These people are ANARCHISTS. Call in our National Guard NOW," Trump tweeted. "The World is watching and laughing at you and Sleepy Joe. Is this what America wants? NO!!!"

Trump urged the city of Philadelphia to call in the National Guard, suggesting the same strategy had been effective in Minneapolis a night earlier despite continued unrest in the Twin Cities after the governor first activated the National Guard on Thursday.

"Other Democrat run Cities and States should look at the total shutdown of Radical Left Anarchists in Minneapolis last night," Trump tweeted Sunday. "The National Guard did a great job, and should be used in other States before it is too late!"

The president retweeted conservative commentator Buck Sexton, a former Hill.TV employee, who wrote late Saturday of the protests: "This isn’t going to stop until the good guys are willing to use overwhelming force against the bad guys."

Trump also lashed out at the media repeatedly on Twitter, accusing the press of fomenting "hatred and anarchy." He also announced his plan to designate antifa as a terrorist organization, though it's unclear what legal authority the government has to do so.

By contrast, presumptive Democratic presidential nominee Joe Biden visited the site of protests in Wilmington, Del., marking just the second time he'd been seen in public amid the ongoing coronavirus pandemic.

The messaging was consistent for Trump, who has struggled to serve as a unifying voice for the country at times of national discord.

Protests have taken place in cities around the country over the past several days in response to the death of George Floyd, an unarmed black man who died after a Minneapolis police officer knelt on his neck for more than eight minutes. The officer has since been fired, arrested and charged with third-degree murder.

The demonstrations have escalated in many cases, with police firing rubber bullets and tear gas into crowds and some protesters vandalizing, looting and setting fire to buildings. Video on Saturday and Sunday showed police cars in New York City and Los Angeles driving into protesters.

In Washington, D.C., protesters have gathered in Lafayette Park near the White House for three straight nights. Trump was reportedly taken into an underground bunker at the complex on Friday night out of caution, and Secret Service reported that more than 60 officers were injured during Saturday night's demonstrations.

The past several days have been a particularly difficult subject for the president to confront given his past remarks on policing and race.

Trump spent months upbraiding NFL players who took a knee in protest of social injustice during the national anthem; he referred to African nations as "shithole countries"; and decried the majority-black city of Baltimore as a "rodent infested mess."

He has also made his support of law enforcement a key part of his appeal to his base. Trump has on multiple occasions called on the city of Chicago to adopt stop-and-frisk to curb violence, and he quipped in 2017 that police officers shouldn't worry about roughing up suspects when placing them in police vehicles. 

The president has at times over the past few days expressed his concern about Floyd's death and encouraged peaceful demonstrations. White House aides on Sunday repeatedly pointed to his remarks on Saturday in Florida, where he attended a SpaceX launch.

"I understand the pain that people are feeling. We support the right of peaceful protesters, and we hear their pleas. But what we are now seeing on the streets of our cities has nothing to do with justice or with peace," he said. "The memory of George Floyd is being dishonored by rioters, looters and anarchists."

The administration is conducting a civil rights investigation into the matter, which Trump has said will be expedited.

But his more measured statements about Floyd's killing and the resulting unrest have been largely overshadowed by his more inflammatory tweets.

The president tweeted early Friday morning that "when the looting starts, the shooting starts" as protests raged in Minneapolis. Trump later said he was unaware of the phrase's origins in the 1960s when a Miami police chief used to describe his willingness to use violence on civil rights protesters.

On Saturday morning, after demonstrations outside the White House reportedly prompted him to retreat to the bunker, Trump tweeted that he "couldn't have felt more safe." He again appeared to threaten an escalation against protesters, saying those outside "would have been greeted with the most vicious dogs, and most ominous weapons, I have ever seen" if they breached the White House gates.

Protests in the capital initially appeared to be more peaceful on Sunday evening than the prior night, though there was some anxiety in downtown Washington. Some business owners preemptively boarded up their windows, and Mayor Muriel Boswer (D) activated the National Guard and imposed a citywide curfew for 11 p.m.

"I think that the president has a responsibility to help calm the nation," Boswer said on "Meet the Press" earlier Sunday. "And he can start by not sending divisive tweets that are meant to harken to the segregationist past of our country."