US prosecutors filed federal hate crimes charges Wednesday against the white gunman accused of targeting Black Americans in a Buffalo, New York grocery store, killing 10 victims and injuring three others.

Attorney General Merrick Garland vowed to "be relentless" in the Justice Department's efforts to combat hate crimes after meeting with the victims' families, and "hold accountable those who perpetrate them."

"No one in this country should have to live in fear that they will go to work or shop at a grocery store and will be attacked by someone who hates them because of the color of their skin," he said during a news conference in Buffalo alongside senior Justice Department officials, including US Attorney for the Western District of New York Trini Ross.

Payton Gendron, 18, now faces 10 federal charges of committing a hate crime resulting in death for each of the victims who were killed May 14 at the Tops Friendly Market. He also faces three counts of committing a hate crime with the intent to kill, as well as 13 firearm violations.

All 10 people who were killed were Black. Two of the injured were white and one was Black.

Federal hate crimes charges carry the possibility of the death penalty. Asked if prosecutors would pursue capital punishment, Garland demurred, saying the department's internal procedures would be followed and the victims' families would be consulted.

He declined to say whether the families he spoke with Wednesday wanted Gendron to face the death penalty.

Gendron already faces murder and hate crimes charges in a state case and it is unclear which prosecution would move forward first./agencies