BUFFALO — President Biden on Tuesday condemned white supremacy and said the nation must “reject the lie” of racism reportedly espoused by the shooter who on Saturday killed 10 Black people at Buffalo.

Speaking to victims’ families, local officials, and first responders, Mr. Biden said America’s diversity is its strength and the nation must not be distorted by a “hateful minority.”

“In America, evil will not win, I promise you,” Mr. Biden said. “Hate will not prevail, white supremacy will not have the last word.”

Mr. Biden spoke after he and first lady Jill Biden paid their respects at a makeshift memorial of blossoms, candles and messages of condolence outside the Tops supermarket, where on Saturday a young man armed with an assault rifle targeted Black people in the deadliest racist attack in America since Mr. Biden took office.

In Buffalo, the president was confronting anew the forces of hatred he frequently says called him back to seek the White House.

“Jill and I have come to stand with you, and to the families, we have come to grieve with you,” Mr. Biden said. He added: “Now’s the time for people of all races, from every background, to speak up as a majority and American and reject white supremacy.”

“It’s important for him to show up for the families and the community and express his condolences,” the president of the NAACP, Derrick Johnson, said. “But we’re more concerned with preventing this from happening in the future.”

It’s unclear how Mr. Biden will try to do that. Asked about gun legislation, Mr. Biden said at the airport, “It’s going to be very difficult. … I’m not going to give up trying.”

Mr. Biden’s condemnation of white supremacy is a message he has delivered several times since he became the first president to specifically address it in an inaugural speech, calling it “domestic terrorism that we must confront.” 

In his remarks Tuesday, Mr. Biden paid tribute to each of the 10 people who lost their lives, describing them as model citizens, beacons of their community and deeply committed to family.

Three more people were wounded. Nearly all the victims were Black, including all of those who died.

“These actions we’ve seen, these hate-filled attacks, represent the views of a hateful minority,” Mr. Biden said.

“We have to refuse to live in a country where black people going about a weekly grocery shopping can be gunned down by weapons of war deployed in a racist cause,” he added. “We have to refuse to live in a country where fear and lies are packaged for power and for profit.”