Earlier Sunday, Biden condemned Saturday's attack, saying that the public must work together to address the "hate that remains a stain on the soul of America."
"A lone gunman, armed with weapons of war and a hate-filled soul, shot and killed 10 innocent people in cold blood at a grocery store on Saturday afternoon," Biden said as he began speaking at the National Peace Officers’ Memorial Service outside the U.S. Capitol.
Biden said he'd been receiving updates from his White House team, who have been in touch with the Justice Department. The Justice Department has said it's investigating the matter as a hate crime, "a racially motivated act of white supremacy and violent extremism," Biden said.
"Our hearts are heavy once again, but our resolve must never ever waver," he added.
A White House official said Biden spoke with New York Gov. Kathy Hochul on Sunday "to offer his condolences and support during this difficult time." Biden also reached out to Buffalo Mayor Byron Brown, the official said.
An 18-year-old white man is accused of shooting 13 people, 11 of them Black people, at a Tops Friendly Market in Buffalo on Saturday.
The suspect, who was taken into custody and arraigned on one count of first-degree murder, is alleged to have written a “manifesto” that included plans to target Black people and repeatedly referred to the "great replacement theory” — the false idea among white supremacists that there's an effort to replace white Americans with immigrants, Jews and other minority groups.
Far-right conspiracy theorists have used the theory to attack such groups.
Vice President Kamala Harris said Sunday that the shooting clearly shows there is an “epidemic of hate across our country that has been evidenced by acts of violence and intolerance.”
“We must call it out and condemn it,” she said in a statement. “Racially motivated hate crimes or acts of violent extremism are harms against all of us, and we must do everything we can to ensure that our communities are safe from such acts.”
House Speaker Nancy Pelosi, D-Calif., said Democrats have repeatedly taken action in Congress to try to reduce gun violence, adding that the House will continue to consider measures to boost efforts to fight domestic terrorism.
She also accused social media and television networks of advancing hatred across the country.
“Another community has been shattered by the horrors of gun violence and the scourge of bigotry, fueled by rampant hatred spreading on social media and on leading television networks — as we have tragically seen in El Paso, Charleston and countless more communities,” Pelosi said, referring to deadly attacks in Texas and South Carolina in recent years. “While authorities continue to investigate this unconscionable attack as an act of hate, let me make crystal clear: Domestic terror has no place in America.”
Hochul, a Democrat who is a native of Buffalo, said Sunday on NBC’s “Meet the Press” that she wants internet companies to be held accountable when they allow people to post extremist content online.
The gunman livestreamed the mass shooting Saturday, authorities said.
“The fact that platforms are willing to share this information, allow it to be posted, a manifesto that’s been out there that describes in great detail how someone wants to have an execution of individuals in a community that’s targeted because it’s the highest Black population within a geographic area, that’s all out there,” she said.
A number of lawmakers in Congress said such hate has to be identified and called out and that action must also be taken to reduce access to assault weapons.
Rep. John Garamendi, D-Calif., said Sunday on Twitter: “The regularity of these mass casualty events and the near constant threat of racist violence is unacceptable. I will continue my decades-long efforts to keep assault rifles off our streets.”
Rep. Brenda Lawrence, D-Mich., tweeted: “Angry & devastated at the racially-motivated terrorist attack in Buffalo last night. Make no mistake: this was an attack on the Black community. We need to call out this hate directly.”
In a tweet Sunday, House Intelligence Committee Chairman Adam Schiff, D-Calif., condemned Fox News host Tucker Carlson for pushing "racist conspiracies like 'the great replacement.'"
"He knows the risks," Schiff wrote. "He knows some view his vile hate as a call to arms."