President Biden on Tuesday called white supremacy a “poison” in the U.S. and called on Americans to reject the racist white “replacement theory” believed to have inspired the gunman behind the tragic Buffalo shooting.

“I call on all Americans to reject the lie,” Biden said in emotional remarks from Buffalo Tuesday afternoon. ”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 victims’ families in 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.”