US President Joe Biden on Tuesday visited the city of Buffalo, New York, following the mass shooting there on Saturday.

In his remarks, Biden called white supremacy a “poison” in the US and called on Americans to reject the racist white “replacement theory” believed to have inspired the gunman who carried out the shooting.

“I call on all Americans to reject the lie,” he said, according to The Hill, adding, “I condemn those who spread the lie for power, for political gain and for profit.”

“We need to say as clearly and forcefully as we can that the ideology of white supremacy has no place in America,” Biden said. “None.”

Biden delivered the remarks after he and First Lady Jill Biden met with families of the victims of Saturday’s mass shooting, which police are investigating as a racially motivated hate crime.

Biden called the weekend shooting that left 10 dead an act of “domestic terrorism.”

“What happened here is simple and straightforward: Terrorism. Terrorism. Domestic terrorism,” Biden said. “Violence inflicted in the service of hate and the vicious thirst for power that defines one group of people being inherently inferior to any other group.”

He called out the media, politics and the internet for radicalizing individuals and spreading the racist “replacement theory” that white people, in particular, are at risk of being replaced by minority groups.

Biden later acknowledged the difficulty of getting Congress to pass gun legislation, telling reporters before departing Buffalo: “It is going to be very difficult, but I am not going to give up.”

The gunman in Saturday’s shooting opened fire at the Tops Friendly Markets, firing a shotgun and two rifles during a six-minute rampage.

The suspect in the shooting has been identified as Payton Gendron, who surrendered to police after the shooting, and has been charged with 10 counts of first-degree murder.

Prior to the shooting, Gendron uploaded a manifesto to the internet, warning of “white genocide”, citing low birthrates among people of European heritage across the globe, and higher birthrates among non-white populations.

A document posted online by the suspect detailed his initial plans weeks before the shooting.

According to the document, obtained by the Washington Post, Gendron refers to the local Tops supermarket as “attack area 1,” also noting two other areas in the city where he can “shoot all blacks.”