Gang members will not be handing in their guns following the law reform announced by Prime Minister Jacinda Ardern, a Mongrel Mob leader has said.

Sonny Fatu, president of the Waikato branch of the Mongrel Mob, said that, while some members of the gang may have illegal guns, they will not be handing them in as they are necessary to their protection.

"Will gangs get rid of their weapons? No. Because of who we are, we can't guarantee our own safety," he told Stuff.

He admitted many of the gang's estimated 1000 associates hold illegal firearms but says they should be trusted not to harm innocent people.

"It's not in our culture to inflict harm on innocent people like what happened in Christchurch," Fatu said.

He says the public should not be afraid of gang members' guns as they are used in gang-on-gang violence only.

"The attacks between our organisations are gang-on-gang, they do not involve the non-gang members. Although there may be peripheral damage and violence that occasionally spills out into the public eye, it is absolutely and without intention for any harm to be caused to non-gang members," he said.

Mongrel Mob members have expressed their sympathy and solidarity with the Muslim community and the victims of the Christchurch terrorist attack.

Members of the Mongrel Mob and Black Power gangs have had public displays of solidarity with the victims, including guarding mosques while Muslim people prayed.