WASHINGTON — President Joe Biden on Friday spoke with the mother and stepfather of Tyre Nichols, the Black man whose beating to death by police officers has set the United States on edge.

Biden told reporters that he was “very concerned” about the potential for violent protests, but that Nichols’ mother, RowVaughn Wells, had made a powerful appeal for calm.

“I was really pleased that she called for peaceful protests — no, no violence,” he said. “She has made a very strong plea.”

Biden said his call, which was also with Nichols’ stepfather Rodney Wells, lasted 10-15 minutes.

The slain man’s mother was “obviously in enormous pain,” Biden said, adding that he sought to comfort her, saying “the time will come when his memory will bring a smile before a tear.”

There were fears of potentially violent protests later Friday when police release what has been described as gruesome video footage of the incident in which five officers, all of them also Black, fatally beat Nichols after a traffic stop.

Press Secretary Karine Jean-Pierre reiterated Biden’s appeal for calm and said the White House was bracing for trouble.

“The White House has been in coordination with the various agencies to ensure they prepare if the protests become violent. This coordination is standard practice.”

“The president has been briefed but he has not seen the video. Nor has anyone else at the White House seen the video,” she said.

Talking about the wider issue of police brutality, she said the “president was very clear we need to deliver change. We must have accountability when law enforcement officers violate their oath and we need to build a long-lasting trust.”

Biden said the way the incident is handled will have an impact on “the image of America.”

“That has a lot do with whether or not we are the country we say we are — that we’re a country of law and order…(where you) peacefully protest,” he said.

The White House said that senior staff had briefed the mayors of more than a dozen cities, including Atlanta, Chicago and Philadelphia, on federal assistance in case of protests.

“Participating mayors shared their perspectives on how important it is to recognize the pain felt by communities across this country, be prepared in advance with a game plan to provide adequate community support, and to reinforce the importance of peace and calm during these difficult moments,” the White House said.