A recording made during a lethal mass shooting in Buffalo, New York, has been banned in New Zealand.

And Cabinet minister Megan Woods says the US shooter's apparent idolisation of the 2019 Christchurch terrorist has retraumatised some in the local Muslim community.

The livestream video of yesterday's mass shooting in the United States has now been banned, Acting Chief Censor Rupert Ablett-Hampson said this morning.

The shooting in a mostly black neighbourhood was live-streamed on the Twitch platform, accompanied with a manifesto, and motivated by anti-black racial hatred.

The footage ban followed Ablett-Hampson's decision yesterday to ban the US terrorist's manifesto.

Ablett-Hampson said the supermarket shooter, who killed ten people, published a written document detailing why he committed mass murder.

The six minute, 52 second video of the attack has been classified as objectionable under the Films, Videos, and Publications Classification Act.

"This footage celebrates the killing of innocent people going about their lives, doing their grocery shopping," Ablett-Hampson added.

"There is no merit in this and it is sadly being shared by people who support the actions of the killer."

He said the US video was comparable in violence and cruelty to footage the Christchurch terrorist recorded in the March 2019 mosque attacks.

Today's ruling made it an offence to possess or distribute the US mass shooting manifesto or livestream recording in New Zealand.

The decision is an interim one, so a final classification will be made later for the manifesto and the footage.

Similarities to the March 2019 attacks have led New Zealand officials to approach American counterparts to offer help.

Woods told Newshub the Muslim community was shaken after hearing the 2019 terrorist reference in the US attacks.

She said the US killer referenced the Christchurch mosque attacks.

The atrocity in Buffalo, New York State's second-largest city, has led to more debate on how to prevent or disable terrorist content online.

"One of the things they did take great heart in was that things could act a lot more swiftly in terms of the online content than what we saw after the March 15 attack," Woods told the AM show.

Former FBI deputy director Andrew McCabe told CNN the 2019 Christchurch terrorist might have inspired the 18-year-old American supermarket shooter.